98334 31475 82706 10252 20225 39858 40061 55008 60021 76062 83223 iii iRixhVV Nddff 1snTTT 2snTdTdTd 3pppp 4PPPP 5appp 6RRRtR 7wwW1W2 8NhCLCMCH sta C/wind Temp DPT StaPres SLP APP Precip Preswx Clouds
BBXX SHIP 24121 99122 71353 31475 82706 10252 20225 40061 55008
BBXX SHIP YYGGIw 99LaLaLa QcLoLoLoLo iRixhVV Nddff 1snTTT 2snTdTdTd 4PPPP 5appp
ID DTG Lat Long Misc Wind Temp DP SLP APP
76062 83223 91312 22242 00234 20805 31215 40806 51005
7wwW1W2 8NhCLCMCH 9GGgg 222DsDv 0SsTwTwTw 2PwPwHwHw 3Dw1Dw1Dw2Dw2 4Pw1Pw1Hw1Hw1 5Pw2Pw2Hw2Hw2
Wea Clouds Ob Time Mvmnt SST Waves Swl dir Primary Secondary
62052 80122 ICE 23223
6IsEsEsRs 8SwTbTbTb ICE ciSibiDizi
Ship ice Wet Bulb Ice Flows
SMVD22 KWBC 011200 RRA BBXX MMMM Type 46014 01121 99392 71240 46/// /0602 10125 40108 53004 91150 22200 IIiii DDHHI 99LaLaLa QcLoLoLoLo II/// /ddff 1snTTT 4PPPP 5APPP 9HHmm 22200 Station Time Lat Long Block Winds Temp SLP APP Obtime 22200 00126 11703 70013 333 91203 555 11024 22025; 0snTsTsTs 1PwPwHwHw 70HwHwHw 333 9SpSpspsp 555 National Data SST Waves Waves 333 special 555 National data
UPPER AIR CODE
Mandatory Levels
TTAA 52121 71853 Part A DTG Station 99001 09421 03003 00050 09421 03003 92750 21424 03011 85525 11056 25014 SFC T/DPD Wind 1000mb T/DPD Wind 925mb T/DPD Wind 850mb T/DPD Wind 70118 10062 11509 50585 03977 00508 40757 14970 31016 30967 32357 26518 25093 427// 700mb T/DPD Wind 500mb T/DPD Wind 400mb T/DPD Wind 300mb T/DPD Wind 250mb T/DPD 26520 20241 511// 29523 15423 639// 26012 10666 701// 30010 Wind 200mb T/DPD Wind 150mb T/DPD Wind 100mb T/DPD Wind 88180 661// 33563 77176 33563 41008 51515 10164 00012 Trop T/DPD Wind Max Wnd Wind Vec diff regional additional dataTop of PageSignificant Levels
TTBB 52122 47991 Part B DTG Station 00010 27438 11898 18828 22893 20444 33575 00236 44545 01958 55533 03326 1st lvl T/DPD Sig lvl T/DPD Sig lvl T/DPD Sig lvl T/DPD Sig lvl T/DPD Sig lvl T/DPD 66493 06715 77422 12549 88398 16150 99391 17160 11386 17950 22380 18757 Sig lvl T/DPD Sig lvl T/DPD Sig lvl T/DPD Sig lvl T/DPD Sig lvl T/DPD Sig lvl T/DPD 31313 74702 81130 61616 11900 11521 22800 11021 33600 11027; 31313 SST and Sounding data 61616 Additional levels developed nationally Additional data is represented by the 21212, 31313, 41414, 51515-59595, and 61616-69696 groups.Pilot Winds
PPBB 52126 47158 Pilot DTG Station 90012 32003 18005 16006 90346 11506 07506 08507 90789 10509 10510 10010 9k123 Wind1 Wind2 Wind3 9k456 Wind4 Wind5 Wind6 9k789 Wind7 Wind8 Wind9 91246 13005 22005 27004 9205/ 32509 30511 9305/ 23014 24524 950// 23016; 9k012 Wind10 Wind11 Wind12 9k34/* Wind13 Wind14 9k56/ Wind15 Wind16 9k7// Wind17 9 is the indicator for the winds at three significant levels (given in the following three groups) k indicates a 10,000 ft range (0 = 0-9000ft, 1=10,000-19,000ft, 2=20,000-29,000ft, etc) The next three numbers each represent the level for the Winds in thousands of feet (90012 = 9=Indicator, 0=Sfc-9000ft range, 0=Sfc wind hgt, 1=1000ft wind hgt, 2=2000ft wind hgt Wind1=Winds corresponding to the 3rd digit in the 9 group, Wind2- the 4th digit, Wind3- the 5th digit. A solidus (/) is entered when there are no more wind levels for that 1000ft range. This pattern repeats for all winds.
SATELLITE DERIVED WINDS CODE
TWNA01 RJTD 031200
ICAO DTG
YYXX 53080 11461 152// 034///
YYXX YYGGg I1I2I2I3I4 I1I2I2// I1I2I2//
Type DTG Satellite Information
333 11704 9727/ 32024 9525/ 31525 7322/ 31038
333 B1B2B3nn ULaULoPePe/ ddfff ULaULoPePe/ ddfff ULaULoPePe/ ddfff
Ind Grid Location Winds Location Winds Location Winds
3722/ 36032
ULaULoPePe/ ddfff
Location Winds
20104 7919/ 07016 3518/ 04018 1120/ 04516
B1B2B3nn ULaULoPePe/ ddfff ULaULoPePe/ ddfff ULaULoPePe/ ddfff
Grid Location Winds Location Winds Location Winds
1724/ 05518
ULaULoPePe/ ddfff
Location Winds
FORECAST CODE (TAF)
KFBG TAF RTD 021111 18010KT 8000 BR SCT040 BKN250 QNH3010INS 620046 510003
ICAO Type Mod Valid Wind Vis Wx Clouds Clouds Altimeter Icing Turbulence
BECMG 1314 22012G18KT 9999 VCTS SCT040 BKN250 QNH3008INS
Change Time New winds Vis Wx Clouds Clouds Altimeter
TEMPO 1718 23015G25KT 4800 TSRA BKN015CB OVC050
Temporary Time Tempo Wind Vis Wx Clouds Clouds
BECMG 2223 22012G18KT 8000 SHRA BR BKN030CB OVC100 QNH3000INS
Change Time New winds Vis Wx Clouds Clouds Altimeter
T25/21Z T18/11Z
Max Temp Min Temp
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METAR CODE
METAR PGUA 181255Z COR 12010G15KT 090V150
METAR or SPECI CCCC YYGGggZ AUTO or COR dddff(f)Gfmfm(fm)KT dndndnVdxdxdx
Type of Report Sta DTG Modifier Wind Variable wind
15SM R03L/1600FT VCSH FEW018CB BKN120 BKN300
VVVVVSM [RDRDR/VRVRVRVRFT or RDRDR/VNVNVNVNVVXVXVXVXFT] w'w' [NsNsNshshshs or VVhshshs or SKC/CLR]
Vis RVR Wx Sky Condition
28/18 A2987 RMK SLP096 CB 7 E MOV NW
T'T'/T'dT'd APHPHPHPH RMK (Automated, Manual, Plain Language)
T/TD Altimeter Remarks
8/378 9/232 55007
(Additive Data and Automated Maintenance Indicators)
Additive Data
RADAR OBSERVATION CODE
SDAS KAWN 271800 RRX
FFAA 29030 47447 42364 11361 10314 30222;
MiMiMjMj YYGGg IIiii 4RwLaLaLa QcLoLoLoLo AcScWcacrt tedsdsfsfs
Type DTG Station Lat Long Char Mvmnt
AUSTRALIAN TROPICAL CYCLONE BOGUS
BTAB messages are coded summaries of tropical cyclone parameters. These messages are transmitted to Darwin RSMC in a specific computer-readable format. The data is then distributed by Darwin for use by international numerical weather prediction centres.
WTAU10 ADRM 271900
BTAB YPDM 02U BESSI 011127 1800 084S 0928E 240 035 0990 1008 0450 20 200 0200 0300 0300 0200 D ;
Sid Stnam Dtg HHmm Lat Long Dir Sm/s ChPa OhPa Rout Max Rad 30NE 30SE 30SW 30NW SD
RECCO CODE
URPA11 PGTW 161227
Standard Message Header
AF967 0212A LILI OB 08 PGTW
Mission data
97779 12314 40169 82508 04000 22020 25218 /0007 42115
9XXX9 GGggI YQLaLaLa LoLoLoBf hhhdtda ddfff TTTdTdw /jHHH 4ddff
Group Time Lat Long Altit Winds T/Td Sfc Pres Sfc Wind
14132 92080 62040 46262 11500 28080 60081 77186 75760 80366 81732
1kNsNsNs ChhHH ChhHH ChhHH 1kNsNsNs ChhHH 6WsSsWddw 7IrItSbSe 7hhHH 8drdrSrOe 8EwElceie
Clouds Hgts Hgts Hgts Clouds Hgts Sig Wx Icing loc Icg Hgt Radar Echo
DROPSONDE CODE
UZPA13 PGTW 061851
XXAA 56185 99251 70786 08158 99016 26444 18501 00140 26247 07004
XXAA YYGGId 99LaLaLa QcLoLoLoLo MMMUlaUlo 99PoPoPo ToToToDoDo dodofofofo P1P1h1h1h1 T1T1T1D1D1 d1d1f1f1f1
ID DTG Lat Long Marsden Surface Data Standard Isobaric Surface
88100 52160 ///// 77200 09045 41210
88PnPnPn TnTnTnDnDn dndnfnfnfn 77PnPnPn dndnfnfnfn 4vbvbvava
Tropopause Data Max Wind Data
61616 AF968 0204A BONNIE OB 04
61616 AFXXX XXXXX XXXXX OB X KXXX
Mission Information
62626 RAINBAND SPL 2635N08996W LST WND 001 MBL WND 04010
62626
Nationally Developed Codes
XXBB 56188 99251 70786 08158 00016 26444 11005 25841
XXBB YYGG8 99LaLaLa QcLoLoLoLo MMMUlaUlo 00PoPoPo ToToToDoDo nonoPoPoPo ToToToDoDo
ID DTG Lat Long Marden SLP SL Temp Sig Lvl T/DPD
31313 09608 81828
31313 srrarasasa 8GGgg
Sounding Information
51515 10166 02050
51515 101XX 0PnPnPnPn
Additional Data Groups
61616 AF968 0204A BONNIE OB 04
61616 AFXXX XXXXX XXXXX OB X KXXX
Mission Information
62626 RAINBAND SPL 2635N08996W LST WND 001 MBL WND 04010
62626
Nationally Developed Codes
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VORTEX REPORT CODE
URPA12 PGTW 051237
VORTEX DATA MESSAGE
A. 05/1237Z
B. 30 DEG 59 MIN N
77 DEG 16 MIN W
C. 700 MB 2695 M
D. 65 KT
E. 050 DEG 80 NM
F. 313 DEG 78 KT
G. 063 DEG 32 NM
H. 954 MB
I. 11 C/ 3082 M
J. 15 C/ 3108 M
K. 13 C/ NA
L. CLOSED WALL
M. C25
N. 12345/7
O. 1/1 NM
P. AF984 1606A FRAN OB 14
MAX FL WIND 105 KT NE QUAD 1051Z. STADIUM EFFECT.
MAX FL TEMP 17C 130/10 NM FROM FL CENTER.
VORTEX DATA CODE
URPA14 PGTW 020031
AF985 1605A EDOUARD OB 16 PGTW
SUPPLEMENTARY VORTEX DATA MESSAGE
Header
01401 10721 13086 10303 04044
01LaLaLa 1LoLoLoLo 1jHHH 1TTTdTd ddfff
02400 20719 23068 20505 06048
02LaLaLa 2LoLoLoLo 2jHHH 2TTTdTd ddfff
03398 30716 33052 30606 07045
03LaLaLa 3LoLoLoLo 3jHHH 3TTTdTd ddfff
04396 40714 43038 40606 06036
04LaLaLa 4LoLoLoLo 4jHHH 4TTTdTd ddfff
05394 50711 53020 50706 06048
05LaLaLa 5LoLoLoLo 5jHHH 5TTTdTd ddfff
06391 60709 63986 60707 05050
06LaLaLa 6LoLoLoLo 6jHHH 6TTTdTd ddfff
07388 70706 73949 70907 04051
07LaLaLa 7LoLoLoLo 7jHHH 7TTTdTd ddfff
08386 80704 83914 80908 04048
08LaLaLa 8LoLoLoLo 8jHHH 8TTTdTd ddfff
09385 90702 93872 91010 04047
09LaLaLa 9LoLoLoLo 9jHHH 9TTTdTd ddfff
10384 00699 03813 01311 04041
10LaLaLa 0LoLoLoLo 0jHHH 0TTTdTd ddfff
MF398 M0717 MF058
MFLaLaLa MLoLoLoLo MFfff
OBS 01 AT 2122Z
OBS 01 AT HHMMZ
OBS XX AT HHMMZ
OBS 10 AT 2205Z
OBS 06 SFC WND /////
OBS 01 SFC WND ddfff
REMARKS;
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Automatic Met Report from an Aircraft
AMDAR YYGG
MANOP Time
ipipip IA...IA LaLaLaLaA LoLoLoLoLoB GGgg ShhIhIhI SSTATATA {SSTdTdTd or UUU} ddd/fff TBBA
Phase ACFT ID Lat Long Time PA Temp DP or RH Wind Turb
SS1S2S3 333 Fhdhdhd VGfgfgfg
System Ind PA(ACARS) Vert Gust(ACARS)
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CODE BREAKDOWNS
SYNOP CODE
iii iRixhVV Nddff 1snTTT 2snTdTdTd 3pppp 4PPPP 5appp 6RRRtR 7wwW1W2 8NhCLCMCH
333 1snTxTxTx 2snTnTnTn 3EsnTgTg 4E'sss 8NsChshs 9SpSpspsp
555 1V'f'/V'f''f' 2snTwTwTw
SECTION 0
iii iRixhVV
SECTION 1
Nddff 1snTTT 2snTdTdTd 3pppp 4PPPP 5appp 6RRRtR 7wwW1W2 8NhCLCMCH
SECTION 3
333 1snTxTxTx (at 1800 UTC) 2snTnTnTn (at 0600 UTC) 3EsnTgTg (at 0600 UTC)
4E'sss (at 0600 UTC) 8NsChshs 9SpSpspsp
SECTION 5
555 1V'f'/V'f''f'' 2snTwTwTw
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Interpretation
SECTION 0
iii Station Number
iRixhVV iR Inclusion or omission of precipitation data
ix Inclusion or omission of weather group
h Height of base of lowest cloud
VV Horizontal visibility
SECTION 1
Nddff N Total Cloud amount
dd Wind direction in tens of degrees
ff Wind speed in knots
1snTTT 1 Indicator
sn Sign of temperature
TTT Dry-bulb temperature to the tenth of a degree Celsius
(10302 = +30.2C)
2snTdTdTd 2 Indicator
sn Sign of temperature
TdTdTd Dew-point temperature to the tenth of a degree Celsius
(20281 = +28.1C)
3pppp 3 Indicator
pppp Station level pressure. Rarely used now. Not used in a station plot.
4PPPP 4 Indicator
PPPP Last four figs. of air pressure (reduced to mean sea level) in millibars
and tenths (49882 = 988.2 mb)
5appp 5 Indicator
a Characteristic of pressure change
ppp Pressure change over last three hours in millibars and tenths
6RRRtR 6 Indicator
RRR Amount of rainfall
tR Duration of period of RRR in units of six hours. Main hours only
At 0001 and 1200 UTC tR=1 At 0600 and 1800 tR=2
7wwW1W2 7 Indicator
ww Present weather, manned station
W1W2 Past weather, manned station
8NhCLCMCH 8 Indicator
Nh Amount of low cloud, or medium cloud if no low cloud present
CL Form of low cloud
CM Form of medium cloud
CH Form of high cloud
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SECTION 3
333 Regional Indicator
1snTxTxTx 1 Indicator
sn Sign of temperature
TxTxTx Maximum temperature 0600-1800 UTC in tenths of a degree
2snTnTnTn 2 Indicator
sn Sign of temperature
TnTnTn Minimum temperature 1800-0600 UTC in tenths of a degree
3EsnTgTg 3 Indicator
E State of ground without snow or measurable ice cover
sn Sign of temperature
TgTg Grass minimum temperature rounded to nearest whole degree
4E'sss 4 Indicator
E' State of ground with snow or measurable ice cover
sss Depth of snow
8NsChshs 8 Indicator
Ns Amount of individual cloud layer
C Form of cloud
hshs Height of base of cloud layer
Up to four layers of significant cloud can be reported (using 8NhChshs groups).
The rules for the selection of significant cloud layers are:
1. The lowest layer of any amount
2. The next lowest layer of 3 oktas (eighths) or more.
3. The next lowest layer of 5 oktas or more.
4. Any cumulonimbus cloud not already reported under 1, 2 or 3 above,
regardless of amount.
Clouds are reported in order of ascending height.
Cumulonimbus cloud reported under rule 4 above would be inserted between the
other groups at its correct height level - regardless of the amount of
Cumulonimbus being reported.
9SpSpspsp 9 Indicator
This group is included when necessary to report special phenomena.
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SECTION 5
555 National indicator (This section is not sent when there are no data to report)
1V'f'/V'f''f'' 1 Indicator
V'V' Visibility in meters (reported when visibility is less than 100 m)
(f')f'f' Speed in knots of the maximum gust in the past hour (>33 kts)
2snTwTwTw 2 Indicator
sn Sign of temperature
TwTwTw Sea temperature in tenths of a degree
CODE TABLES
Table 1:iR Indicator for inclusion or omission of precipitation data
Code
Figure Precipitation data are reported: Group 6RRRtR is:
1 in Section 1 included
2 in Section 3 included
3 in none of the two Sections 1 and 3 omitted (precipitation amount =0)
4 in none of the two Sections 1 and 3 omitted (precipitation amount not available)
Note: UK practice only, code figures 1,3 and 4 to be used
Table 2:ix Indicator for type of station operation (manned or automatic)
and for present and past weather
Code
figure Type of station operation Group 7wwW1W2 or 7wawaWa1Wa2 is:
1 manned included
2 manned omitted (no significant phenomena to report)
3 manned omitted (not observed, data not available
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Section 0 BBXX DDDD YYGGi w 99LaLaLa QcLoLoLoLo.
DDDD. This is the four letter ship international radio call sign (IRCS). This group
is entered on the observation form and is transmitted in the observation. This is
the only group with only four elements in the code.
YYGGiw. This group identifies the date and time of the observation, and information
about the wind group.
a. YY - The day of the month (UTC) in two digits, i.e., the second is entered as 02,
the thirteenth as 13, etc. Note that the date UTC will vary by a day from the date
LST on certain hours of the day, depending on the time zone.
b. GG - The hour of observation (UTC) in two digits, i.e., 0900 UTC is entered as 09,
1200 UTC as 12, etc. Observation times are at three hour intervals starting at 0000
UTC, i.e., 00, 03, 06, etc.
c. iw - Navy ships will report wind speed in knots. The code figure indicating how
the wind speed was observed and encode is as follows:
(1) If wind speed is estimated: Code figure 3.
(2) If wind speed is measured: Code figure 4.
99LaLaLa. This group identifies the latitude of
the ship at the time of observation.
a. 99 - Indicates that latitude information follows.
b. LaLaLa - The latitude to the tenth of a degree. To obtain the tenths value, divide
the minutes of latitude by 6 and disregard the remainder.
QcLoLoLoLo. The group identifies the quadrant of the globe that the ship is in and the
longitude of the ship at the time of observation.
a. Qc - The code figure that indicates the quadrant of the globe the ship is in.
b. LoLoLoLo - The longitude to the tenth of a degree.
To obtain the tenths value divide the minutes of longitude by 6 and disregard the remainder.
Qc - Quadrant of the Globe
N
|
Q = 7 | Q = 1
W --------- |---------- E Equator
Q = 5 | Q = 3
|
S
Code
Figure Latitude Longitude
1 North East
3 South East
5 South West
7 North West
NOTE: The choice is left to the observer in the following cases:
When the ship is on the Greenwich meridian or the 180th meridian
(LoLoLoLo = 0000 or 1800 respectively):
Qc = 1 or 7 (northern hemisphere) or
Qc = 3 or 5 (southern hemisphere)
When the ship is on the Equator (LaLaLa = 000):
Qc = 1 or 3 (eastern longitude) or
Qc = 5 or 7 (western longitude)
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9GGgg. This group identifies if the actual time of the observation is not within 10 minutes
of the standard reporting time. Since most observation reports are made within ten minutes
of the standard time, this group will usually not be included.
a. 9 - Indicator.
b. GG - Time in whole hours UTC.
c. gg - Time in whole minutes UTC.
222Dsvs. This group identifies the direction and speed of the ship.
a. 222 - Identifies the beginning of section 2 of the code.
b. Ds - The code figure representing the direction of the movement of the ship during the
three hours preceding the time of observation.
c. vs - The code figure indicating the average speed made good during the three hours
preceding the time of observation.
OssTwTwTw. This group indicates the sea water temperature in degrees Celsius.
a. O - Identifies the sea water temperature group in section 2 of the code. If the
temperature cannot be observed, the entire group is deleted from the observation and group
O will not appear in section 2.
b. ss - The code figure indicating the sign and type of sea water temperature.
c. TwTwTw - The sea water temperature in tens, units, and tenths degrees Celsius.
2PwPwHwHw. This group indicates the wind wave data determined from visual observation.
a. 2 - Identifies the wind wave group in section 2 of the code.
b. PwPw - The average period of the significant wind waves in seconds. A period of three
seconds is entered as 03, a period of twelve seconds as 12. Calm is entered as 00, 99 if
period is confused.
c. HwHw - The code figure indicating the height of the wind waves.
3dw1dw1dw2dw2. This group indicates the directions of the primary and secondary swell waves.
a. 3 - Identifies the swell wave direction group in section 2 of the code. If element is
not observed it is encoded as 30000.
b. dw1dw1 - Hundreds and tens of degrees of the direction from which the primary swell is
coming from.
c. dw2dw2 - Hundreds and tens of degrees of the direction from which the secondary swell is
coming from.
If there is only one swell present, "00" is entered for dw2dw2.
4Pw1Pw1Hw1Hw1. This group indicates the primary swell wave data.
a. 4 - Identifies the primary swell wave group in section 2 of the code when no swell is
present. If the element is not observed, 40000 is encoded.
b. Pw1Pw1 - The average period of the primary swell waves in seconds. A period of three
seconds is 03, a period of twelve seconds is 12, etc..
c. Hw1Hw1 - The code figure indicating the height of the primary swell waves.
5Pw2Pw2Hw2Hw2. This group indicates the secondary swell wave group in section 2 of the code.
If the element is not observed, it is encoded as 50000.
a. Pw2Pw2 - The average period of the primary swell waves in seconds. A period of three
seconds is 03, a period of twelve seconds is 12, etc.
b. Hw2Hw2 - The code figure indicating the height of the primary swell waves.
6IsEsEsRs. This group identifies the state of ice accretion on the ship at the time of
observation. The entire group is omitted from the report if ice is not observed.
a. 6 - Identifies the ice accretion group in section 2 of the code.
b. Is - The code figure identifying the source of the ice accretion.
c. EsEs - The average thickness of the ice in centimeters.
d. Rs - The code figure identifying the rate of buildup of the ice accretion.
8SwTbTbTb.This group identifies the wet-bulb temperature in degrees Celsius.
a. 8 - Identifies the wet bulb temperature group in section 2 of the code.
b. Sw- The sign and type of wet-bulb temperature.
c. TbTbTb - The wet-bulb temperature in tens, units, and tenths degree Celsius.
ICE + Plain Language or ICE ciSibiDizi. This group identifies the presence and state of sea ice
and ice of land origin.
a. ICE - Indicates that the sea ice group is present in section 2 of the code. When no sea
ice or ice of land origin is observed, this group will be omitted from the code.
b. ci - The code figure that best describes the concentration and arrangement of the sea ice
at the time of observation.
c. Si - The code figure that best describes the stage of development of the sea ice at the
time of observation.
d. bi - The code figure that best describes the ice of land origin present at the time of
observation.
e. Di - The code figure that best describes the orientation of the principle edge of the sea
ice at the time of observation.
f. zi - The code figure that best describes the effect of the sea ice on the ship over the
past three hours.
g. Plain Language - Remarks considered significant by the observer.
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MMMM. Bulletin type for data.
IIiii. WMO block and buoy identifier.
DDHHI. Date Time Group.
a. DD. Day of the month in two digits.
b. HH. Zulu hour for the observation.
c. I. Indicator for the source of wind speed. 1 or 2 = knots, 3 or 4 = meters per second.
99LaLaLa. Latitude. Standard group for latitude
a. 99. Indicator for the group.
b. LaLaLa. Latitude reported to the nearest tenth of a degree.
QcLoLoLoLo. Longitude. Standard group for longitude.
a. Qc. Quadrant of the globe.
1 = N and E
3 = S and E
5 = S and W
7 = N and W
b. LoLoLoLo. Longitude to the nearest tenth of a degree.
II///. WMO Block.
/ddff. Winds.
a. dd. Wind direction to the nearest ten degrees in two digits (hundreds and tens digits)
b. ff. Wind speed.
1SnTTT. Temperature.
a. 1. Indicator for the group.
b. Sn. Sign of the temperature. 0 = positive, 1 = negative.
c. TTT. Temperature to the nearest tenth of a degree Celsius.
4PPPP. Air pressure at mean sea level.
5APPP. Pressure tendency group
a. 5. Indicator for the group.
b. A. Coded tendency number
c. PPP. Pressure change.
9HHMM. Actual time the observation was taken.
a. 9. Indicator for the group.
b. HH. Hour of the observation.
c. MM. Minute of the observation.
22200. Indicator for observed maritime conditions.
0snTsTsTs. Sea Surface Temperature group.
a. 0. Indicator for the group.
b. sn. Sign of the SST.
c. TsTsTs. Sea Surface Temperature in tenths of a degree Celsius.
1PwPwHwHw. Wave period and height.
a. 1. Indicator for the group.
b. PwPw. Wave period.
c. HwHw. Wave height to the nearest 10 meters.
70HwHwHw. Additional Wave data.
a. 70. Indicator for the group.
b. HwHwHw. Wave height to the nearest meter.
333. Indicator for regionally assigned data.
9SpSpSpSp. Special data.
555. Nationally assigned data.
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TTAA 52121 71853 99001 09421 03003 00050 09421 03003 85525 11056 25014 TTAA YYGGI IIiii 99PoPoPo ToToTaoDoDo dododofofo 00hhh TTTaDD dddff 85hhh TTTaDD dddff 88180 661// 33563 77176 33563 41008 51515 10164 00012 88PtPtPt TtTtTatDtDt dtdtdtftft 77PmPmPm dmdmdmfmfm vbvb0vava 51515 101AdfAdf TTAA. Identifies Part A of the Temp Ship code. YYGGI Date Time Group. a. YY. Identifies the date in two digits. b. GG. Identifies the zulu hour in two digits. c. I. Indicates the highest mandatory level for which winds are reported. IIiii. The station block and number. 99popopo Indicator for surface data. a. 99. Indicator. b. popopo. The code for the surface pressure. TtTtTatDtDt Temperature and Dew Point Depression at the surface. a. TtTt. Surface temperature in degrees Celsius. b. Tat. Sign for the surface temperature. 0=positive temps, 1=negative temps. c. DtDt. Dew Point Depression for the Surface. Subtract this from the temperature to get surface Dew Point. dtdtdtftft Surface winds. a. dtdtdt. Wind direction to the nearest 5 degrees. For wind speeds over 100 knots, 1 is added to the direction. (ex: 112 degrees at 112 kts = 11112, 110 degrees plus 1. 115 degrees at 112 kts = 11612, 115 degrees plus 1) b. ftft. Wind speed in whole knots. 00hhh 1000mb level pressure height. a. 00. Indicator for 1000mb data. b. hhh. Coded pressure height. TTTaDD Temperature and dew point for the pressure level a. TT. Pressure level temperature in degrees Celsius. b. Ta. Sign for the temperature. 0=positive temps, 1=negative temps. c. DD. Dew Point Depression for the pressure level. Subtract this from the temperature to get the Dew Point. dddff Wind at the pressure level. a. ddd. Wind direction to the nearest 5 degrees. For wind speeds over 100 knots, 1 is added to the direction. b. ff. Wind speed in whole knots. 85hhh 850mb level pressure height. a. 85. Indicator for the 850 mb height. b. hhh. Coded pressure height. TTTaDD Temperature and dew point for the pressure level a. TT. Pressure level temperature in degrees Celsius. b. Ta. Sign for the temperature. 0=positive temps, 1=negative temps. c. DD. Dew Point Depression for the pressure level. Subtract this from the temperature to get the Dew Point. dddff Wind at the pressure level. a. ddd. Wind direction to the nearest 5 degrees. For wind speeds over 100 knots, 1 is added to the direction. b. ff. Wind speed in whole knots. 88PtPtPt Tropopause data. a. 88. Indicator for tropopause data. b. PtPtPt. Pressure height of the tropopause. TtTtTatDtDt Temperature and dew point for the pressure level a. TtTt. Tropopause temperature in degrees Celsius. b. Tat. Sign for the tropopause temperature. 0=positive temps, 1=negative temps. c. DtDt. Dew Point Depression for the tropopause. Subtract this from the temperature to get trop Dew Point. dtdtdtftft Winds at the Tropopause. a. dtdtdt. Wind direction to the nearest 5 degrees. For wind speeds over 100 knots, 1 is added to the direction. b. ftft. Wind speed in whole knots. 77PmPmPm Max wind pressure level. (if this is at or above the data field group starts with 66) a. 77. Indicator for the Max Wind data. b. PmPmPm. Coded pressure at the Maximum Wind Level. dmdmdmfmfm Maximum winds a. dmdmdm. Wind direction to the nearest 5 degrees. For wind speeds over 100 knots, 1 is added to the direction. b. fmfm. Wind speed in whole knots. VbVb0VaVa Vector difference above and below the max wind level. a. VbVb. Vector difference between the Max wind level and the winds 3000 feet below. b. VaVa. Vector difference between the Max wind level and the winds 3000 feet above. 21212 -Data for additional levels, with respect to winds. 31313 -Data for Sea Surface Temperature and Sounding System. 41414 -Wind data. 51515 101AdfAdf. Coded data assigned regionally. 51515-59595 -Code groups developed regionally. 61616-69696 -Code groups developed nationally. Top of Page
TTBB 5212/ 71853 TTBB YYGG/ IIiii 00975 09421 11921 14457 00ppp TTTaDD 11ppp TTTaDD PPBB 52120 72764 PPBB YYGGa IIiii 90023 12507 14511 18518 9tnu1u2u3 dddff dddff dddff TTBB. Indicator for Part B of the Temp Ship bulletin. YYGG/. Date and hour of the observation. IIiiii. Station block and number. 00ppp. First significant level. Each additional level is numbered accordingly. a. 00. Indicator for group. b. ppp. Pressure height for the group. TTTaDD. Temperature and dew point for the pressure level a. TT. Pressure level temperature in degrees Celsius. b. Ta. Sign for the temperature. 0=positive temps, 1=negative temps. c. DD. Dew Point Depression for the pressure level. Subtract this from the temperature to get the Dew Point. PPBB. Indicator for the Pilot Ship winds report. YYGGa. Date Time Group. a. YY. Identifies the date in two digits. b. GG. Identifies the zulu hour in two digits. c. a. Indicator specifying type of wind measuring equipment used (0- pressure and wind instruments; 1,2- theodolite; 3- radar; 4- same as 0, but the equipment failed during the ascent.) 9tnu1u2u3. Identifies the heights of the following three wind groups. a. 9. Indicator for this group. b. tn Tens digit of the altitude, expressed in increments of 10,000' MSL applying to the data groups which follow. Example: "4" means winds between 40.000' and 50,000' MSL follow. c. u1,u2,u3 Units digit of the altitude, expressed in increments of 1,000 feet, which applies to the first, second, and third data groups following. dddff. Wind at the identified level. a. ddd. Wind direction to the nearest 5 degrees. For wind speeds over 100 knots, 1 is added to the direction. b. ff. Wind speed in whole knots.Top of Page
ICAO Reporting Station.
DTG Date Time Group of Bulletin.
YYXX Bulletin Type.
YYGGg Valid time of report.
a. YY. Day of the month. If 50 is added to the date, winds are reported in knots.
If not winds are in Meters per second.
b. GG. Valid hour (08=0800 Zulu).
c. g. Valid time in tens of minutes.
I1I2I2I3I4 I1I2I2// I1I2I2// Coded information pertaining to the satellite used.
333 Indicator for wind data at specified pressure levels.
B1B2B3nn Grid and number of reports for the grid.
a. B1 Quadrant of the globe.
Code Code
Figure Longitude Hemisphere Figure Longitude Hemisphere
0 0o- 90oW Northern 5 0o- 90oW Southern
1 90o-180oW Northern 6 90o-180oW Southern
2 180o- 90oE Northern 7 180o- 90oE Southern
3 90o- 0oE Northern 8 90o- 0oE Southern
b. B2. Tens digit for the latitude (3 = 30 degrees).
c. B3. Tens digit for the longitude (3 = 30 or 130 degrees depending on the quadrant of the globe).
d. nn. Number of consecutive isobaric surface wind reports for this grid square.
ULaULoPePe/ Location within the grid and Pressure level.
a. ULa. Latitude digit. Equals one degree latitude within the 10o X 10o grid square.
b. ULo. Longitude digit. Equals one degree longitude within the 10o X 10o grid square.
c. PePe. Estimated pressure in tens of hectopascals where cloud displacement was observed.
dddff Winds.
a. ddd. Wind direction to the nearest 5 degrees (third digit being a 0 or a 5 unless speed exceeds 100).
b. ff. Wind speed to the nearest whole number (knots or meters per second). For speeds exceeding 100, a 1 is added to the
digits (third number of the wind group) of the direction. This makes the ones digit of the wind direction either a 1 or a 5.
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ICAO
Location identifier. This four letter identifier states the location that
the forecast is valid for. i.e BECMG states that there's a gradual change in the
weather between 1300Z and 1400Z.
Type
Message Type- TAF(Terminal Airdrome Forecast).
Mod
Modifier (AMD, COR, AMD COR, RTD).
a. AMD - Forecast was amended.
b. COR - Forecast was corrected.
c. AMD COR - Forecast was initially amended then corrected.
d. RTD - Forecast was transmitted late.
Valid
Valid Period. The valid period consists of the current date and the 24 hr.
period of the forecast.
Wind
Surface Wind Direction, Speed, and Gust if any.
a. ddd. Forecast true wind direction (from which wind is blowing) to the nearest 10 degrees.
b. ff. Mean forecast wind speed in whole knots (KT) which is the unit indicator for speed.
c. Ggg. Maximum wind speed in whole knots (KT).
Vis
Forecast prevailing visibility in meters. Whenever
visibility is forecast to be 9000 or less, the weather phenomena, obscuration to
visibility, or vicinity remark will be included.
Visibility Conversion
Statute Statute Statute
Meters Miles Meters Miles Meters Miles
------ ------- ------ ------- ------ -------
0000 0 1200 3/4 3000 1 7/8
0100 1/16 1400 7/8 3200 2
0200 1/8 1600 1 3600 2 1/4
0300 3/16 1800 1 1/8 4000 2 1/2
0400 1/4 2000 1 1/4 4400 2 3/4
0500 5/16 2200 1 3/8 4800 3
0600 3/8 2400 1 1/2 6000 4
0800 1/2 2600 1 5/8 8000 5
1000 5/8 2800 1 3/4 9000 6
9999 7+
|
| INTENSITY | DESCRIPTOR | PRECIPITATION | OBSCURATION | OTHER |
| - Light | MI Shallow | DZ Drizzle | BR Mist | PO Dust/Sand Whirls |
| Moderate | PR Partial | RA Rain | FG Fog | SQ Squalls |
| + Heavy | BC Patches | SN Snow | FU Smoke | FC Funnel Cloud/Tornado |
| DR Drifting | SG Snow Grains | VA Volcanic Ash | SS Sandstorm | |
| VC Vicinity | BL Blowing | IC Ice Crystals | DU Dust | DS Duststorm |
| SH Showers | IP Ice Pellets | SA Sand | ||
| TS Thunderstorm | GR Hail | HZ Haze | NSW No Significant Weather | |
| FZ Freezing | GS Small Hail or Snow Pellets | PY Spray |
Wx
Forecast weather phenomena, obstruction to visibility, or
vicinity remark which will cause visibility to decrease or weather that is expected
within 5 to 10 miles (vicinity e.g. VCTS).
Clouds
Cloud layer group. This group has two sections:
Cloud amount: SKC (no clouds), FEW (TRACE to 2 oktas),
SCT (3 to 4 oktas), BKN (5 to 7 oktas), and OVC (8 oktas).
Cloud heights: Forecast height (AGL) of cloud base to
nearest 100 feet from surface (040; ten thousands, thousands, and hundreds of feet).
Altimeter
Minimum altimeter setting. (30.10 inches)
Icing
Icing Group.
6. Icing Indicator.
2. Type of Icing forecast.
004. Height of the icing layer base in hundreds of feet AGL.
6. Thickness of the icing layer in thousands of feet AGL.
| Code Figure | Type of Icing |
0 |
No Icing |
1 |
Light Icing (mixed) |
2 |
Light Icing in cloud (RIME) |
3 |
Light Icing in precipitation (clear) |
4 |
Moderate Icing (mixed) |
5 |
Moderate Icing in cloud (Rime) |
6 |
Moderate Icing in precipitation (clear) |
7 |
Severe Icing (mixed) |
8 |
Severe Icing in cloud (Rime) |
9 |
Severe Icing in precipitation (clear) |
Turbulence
Turbulence Group.
5. Turbulence Indicator.
1. Turbulence type and intensity.
000. Height of the turbulence layer base in hundreds of feet AGL.
3. Thickness of the turbulence layer in thousands of feet AGL.
| Code Figure | Turbulence Type & Intensity |
0 |
None |
1 |
Light Turbulence |
2 |
Moderate clear air Turbulence, occasional |
3 |
Moderate clear air Turbulence, frequent |
4 |
Moderate in cloud Turbulence, occasional |
5 |
Moderate in cloud Turbulence, frequent |
6 |
Severe clear air Turbulence, occasional |
7 |
Severe clear air Turbulence, frequent |
8 |
Severe in cloud Turbulence, occasional |
9 |
Severe in cloud Turbulence, frequent |
X |
Extreme Turbulence |
Occasional |
Occuring less than 1/3 of the time |
Change
Change group.
Indicates that the predominant conditions will be changing during the given time period.
Change Time
The time period for which the forecasted conditions will change.
The first two numbers indicate the start of the change period and the last two numbers
indicate the time the change should be completed. (BECMG 1314 = conditions will change
between 13 and 14Z to...)
Temporary
Temporary conditions.
Indicates that the following conditions will be experienced temporarily during the
given time period.
Tempo Time
Time period of the temporary conditions.
The first two numbers indicate the earliest the conditions could take place, the last two
numbers indicate the latest the conditions could take place. (TEMPO 1318= The following
conditions may temporarily occur between 13Z and 18Z)
Max/Min Temp
The Forecast Surface Temperature Group.
T - an indicator, meaning temperature
25 - the forecast max/min temperature in whole degrees Celsius (C)
21Z - the valid time to the nearest whole hour UTC of the temperature forecast
and Z is an abbreviated symbol meaning Universal Coordinated Time (UTC)
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Type of Report (METAR and SPECI). The type, METAR or SPECI, shall be included in all reports. The type of report shall be separated from elements following it by a space. Whenever SPECI criteria are met at the time of the routine METAR, the type of report shall be METAR.
Station Identifier (CCCC). The station identifier, CCCC, shall be included in all reports to identify the station to which the coded report applies. The station identifier shall consist of four alphabetic-only characters if the METAR/SPECI is transmitted long-line. The agency with operational control when the station is first established shall be responsible for coordinating the location identifier with the FAA. A list of approved identifiers can be found in the FAA Manual 7350 Series, Location Identifiers.
Date and Time of Report (YYGGggZ). The date, YY, and time, GGgg, shall be included in all reports. The time shall be the actual time of the report or when the criteria for a SPECI is met or noted (see paragraph 2.6.4). If the report is a correction to a previously disseminated report, the time of the corrected report shall be the same time used in the report being corrected. The date and time group always ends with a Z indicating Zulu time (or UTC). For example, METAR KDCA 210855Z would be the 0900 scheduled report from station KDCA taken at 0855 UTC on the 21st of the month.
Report Modifier (AUTO or COR). The report modifier, AUTO, identifies the METAR/SPECI as a fully automated report with no human intervention or oversight. In the event of a corrected METAR or SPECI, the report modifier, COR, shall be substituted in place of AUTO.
Wind Group (dddff(f)Gfmfm(fm)KT_dndndnVdxdxdx). The standards for observing and reporting wind are described in Chapter 5.
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The wind direction, ddd, shall be coded in tens of degrees using three figures. Directions less than
100 degrees shall be preceded with a "0". For example, a wind direction of 90 is coded as "090".
The wind speed, ff(f), shall be coded in two or three digits immediately following the wind direction.
The wind speed shall be coded, in whole knots, using the units and tens digits and, if required, the
hundreds digit. Speeds of less than 10 knots shall be coded using a leading zero. The wind group
shall always end with KT to indicate that wind speeds are reported in knots. For example, a wind
speed of 8 knots shall be coded "08KT"; a wind speed of 112 knots shall be coded "112KT".
a. Gust. Wind gusts shall be coded in the format,
Gfmfm(fm) (see paragraphs 5.4.4 and 5.5.4). The wind
gust shall be coded in two or three digits immediately
following the wind speed. The wind gust shall be coded, in
whole knots, using the units and tens digits and, if required,
the hundreds digit. For example, a wind from due west at
20 knots with gusts to 35 knots would be coded "27020G35KT".
b. Variable Wind Direction (Speeds 6 knots or less). Variable
wind direction with wind speed 6 knots or less may be coded as
VRB in place of the ddd (see paragraphs 5.4.2 and
5.5.3). For example, if the wind is variable at three knots,
it would be coded "VRB03KT".
c. Variable Wind Direction (Speeds greater than 6 knots).
Variable wind direction with wind speed greater than 6 knots
shall be coded in the format, dndndnVdxdxdx. The variable
wind direction group shall immediately follow the wind group
(see paragraphs 5.4.2 and 5.5.3). The directional variability
shall be coded in a clockwise direction. For example, if
the wind is variable from 180 to 240 at 10 knots, it would be
coded "21010KT 180V240".
d. Calm Wind. Calm wind shall be coded as "00000KT"
(see paragraph 5.5.2).
Visibility Group (VVVVVSM). The standards for observing and reporting visibility are
described in Chapter 6.The surface visibility, VVVVVSM, shall be coded in statute miles using the values listed in Table 12- 1. A space shall be coded between whole numbers and fractions of reportable visibility values. The visibility group shall always end with SM to indicate that the visibility is in statute miles. For example, a visibility of one and a half statute miles would be coded "1 1/2SM".
Automated stations shall use an M to indicate "less than" when reporting visibility. For example, "M1/4SM" means a visibility of less than one-quarter statute mile.
| Source of Visibility Report | |||||||
|---|---|---|---|---|---|---|---|
| Automated | Manual | ||||||
| M¼ | 2 | 9¹ | 0 | 5/8 | 1 5/8 | 4 | 12 |
| ¼ | 2½ | 10 | 1/16 | ¾ | 1¾ | 5 | 13 |
| ½ | 3 | 1/8 | 7/8 | 1 7/8 | 6 | 14 | |
| ¾ | 4 | 3/16 | 1 | 2 | 7 | 15 | |
| 1 | 5 | ¼ | 1 1/8 | 2¼ | 8 | 20 | |
| 1¼ | 6¹ | 5/16 | 1¼ | 2½ | 9 | 25 | |
| 1½ | 7 | 3/8 | 1 3/8 | 2¾ | 10 | 30 | |
| 1¾ | 8¹ | ½ | 1½ | 3 | 11 | 35² | |
| Note 1: These values may not be reported by some automated stations. Note 2: Further values in increments of 5 statue mailes may be reported, i.e., 40, 45, 50, etc. |
|||||||
a. RVR shall be coded in the format RDRDR/VRVRVRVRFT,
where R indicates that the runway number follows,
DRDR is the runway number (an additional DR may
be used for runway approach directions, such as R for
right, L for left, and C for center), VRVRVRVR
is the constant reportable value, and FT indicates that
units of measurement are feet. A solidus "/" without spaces
separates the runway number from the constant reportable value.
For example, an RVR value for runway 01L of 800 feet would be
coded "R01L/0800FT".
b. RVR that is varying shall be coded in the format,
RDRDR/VnVnVnVnVVxVxVxVxFT, where R indicates that
the runway number follows, DRDR is the runway number
(an additional DR may be used for runway approach directions,
such as R for right, L for left, and C for
center), VnVnVnVn is the lowest reportable value in feet,
V separates lowest and highest visual range values,
VxVxVxVx is the highest reportable value, and FT
indicates that units of measurement are feet. A solidus "/"
without spaces separates the runway number from the reportable
values. For example, the 10-minute RVR for runway 01L varying
between 600 and 1,000 feet would be coded "R01L/0600V1000FT".
c. The values shall be based on light setting 5 at manual stations
regardless of the light setting actually in use (see Appendix D).
RVR values shall be coded in increments of 100 feet up to 1,000
feet, increments of 200 feet from 1,000 feet to 3,000 feet, and
increments of 500 feet from 3,000 feet to 6,000 feet. Manual
RVR shall not be reported below 600 feet. For automated stations,
RVR may be reported from up to four designated runways.
d. If the RVR is less than its lowest reportable value, the
VRVRVRVR or VnVnVnVn groups shall be preceded by
M. If the RVR is greater than its highest reportable value,
the VRVRVRVR or VxVxVxVx groups shall be preceded by
a P. For example, an RVR for runway 01L of less than 600
feet will be coded "R01L/M0600FT"; an RVR for runway 27 of greater
than 6,000 feet will be coded "R27/P6000FT".
Present Weather Group (w'w'). The standards for observing and reporting present weather
are described in Chapter 8. The appropriate notations found in Table 12-2 shall be used to code present weather.
| QUALIFIER | WEATHER PHENOMENA | |||
|---|---|---|---|---|
| INTENSITY OR PROXIMITY 1 |
DESCRIPTOR 2 |
PRECIPITATION 3 |
OBSCURATION 4 |
OTHER 5 |
- Light Moderate (see note 2) + Heavy VC In the Vicinity (see note 3) |
MI Shallow PR Partial BC Patches DR Low Drifting BL Blowing SH Shower(s) TS Thunderstorm FZ Freezing |
DZ Drizzle RA Rain SN Snow SG Snow Grains IC Ice Crystals PE Ice Pellets GR Hail GS Small Hail and/or Snow Pellets UP Unknown Precipitation |
BR Mist FG Fog FU Smoke VA Volcanic Ash DU Widespread Dust SA Sand HZ Haze PY Spray |
PO Well- Developed Dust/Sand Whirls SQ Squalls FC Funnel Cloud Tornado Waterspout (see note 4) SS Sandstorm SS Duststorm |
1. The weather groups shall be constructed by considering columns 1 to 5 in the table above in sequence, i.e. intensity, followed by description, followed by weather phenomena, e.g. heavy rain shower(s) is coded as +SHRA 2. To denote moderate intensity no entry or symbol is used. 3. See paragraph 8.4.1.a.(2), 8.5, and 8.5.1 for vicinity definitions. 4. Tornados and waterspouts shall be coded as +FC. |
||||
Weather occurring at the point of observation (at the station) or in the vicinity of the station shall be coded in the body of the report; weather observed but not occurring at the point of observation (at the station) or in the vicinity of the station shall be coded in Remarks. With the exceptions of volcanic ash, low drifting dust, low drifting sand, low drifting snow, shallow fog, partial fog, and patches (of) fog, an obscuration shall be coded in the body of the report if the surface visibility is less than 7 miles or considered operationally significant. Volcanic ash shall always be coded when observed. Separate groups shall be used for each type of present weather. Each group shall be separated from the other by a space. METAR/SPECI shall contain no more than three present weather groups. The weather groups shall be constructed by considering columns 1 to 5 in Table 12-2 in sequence, i.e., intensity, followed by description, followed by weather phenomena, e.g., heavy rain shower(s) is coded as +SHRA.
a. Intensity or Proximity Qualifier.
(1) Intensity shall be coded with precipitation types, except ice crystals and hail,
including those associated with a thunderstorm (TS) and those of a showery nature
(SH). Tornadoes and waterspouts shall be coded as +FC. No intensity
shall be ascribed to the obscurations of blowing dust (BLDU), blowing sand
(BLSA), and blowing snow (BLSN). Only moderate or heavy intensity
shall be ascribed to sandstorm (SS) and duststorm (DS).
(2) The proximity qualifier for vicinity, VC, (weather phenomena observed in
the vicinity of but not at the point(s) of observation) shall be coded in
combination with thunderstorm (TS), fog (FG), shower(s) (SH),
well-developed dust/sand whirls (PO), blowing dust (BLDU), blowing
sand (BLSA), blowing snow (BLSN), sandstorm (SS), and
duststorm (DS). Intensity qualifiers shall not be coded with VC.
VCFG shall be coded to report any type of fog in the vicinity of the
point(s) of observation.
Precipitation not occurring at the point of observation but within 10 statute
miles shall be coded as showers in the vicinity (VCSH).
b. Descriptor Qualifier. Only one descriptor shall be coded for each weather
phenomena group, e.g., "-FZDZ". Mist (BR) shall not be coded with any
descriptor.
(1) The descriptors shallow (MI), partial (PR), and patches (BC)
shall only be coded with FG, e.g., "MIFG".
(2) The descriptors low drifting (DR) and blowing (BL) shall only
be coded with dust (DU), sand (SA), and snow (SN), e.g.,
"BLSN" or "DRSN". DR shall be coded for DU, SA, or
SN raised by the wind to less than six feet above the ground.
When blowing snow is observed with snow falling from clouds, both phenomena are
reported, e.g., "SN BLSN". If there is blowing snow and the observer cannot
determine whether or not snow is also falling, then BLSN shall be
reported. PY shall be coded only with blowing (BL).
(3) The descriptor shower(s) (SH) shall be coded only with one or more
of the precipitation types of rain (RA), snow (SN), ice
pellets (PE), small hail (GS), or large hail (GR).
The SH descriptor indicates showery-type precipitation. When
any type of precipitation is coded with VC, the intensity and
type of precipitation shall not be coded.
(4) The descriptor thunderstorm (TS) may be coded by itself, i.e.,
a thunderstorm without associated precipitation, or it may be coded
with the precipitation types of rain (RA), snow (SN),
ice pellets (PE), small hail and/or snow pellets (GS),
or hail (GR). For example, a thunderstorm with snow and small
hail and/or snow pellets would be coded as "TSSNGS". TS shall
not be coded with SH.
(5) The descriptor freezing (FZ) shall only be coded in combination
with fog (FG), drizzle (DZ), or rain (RA), e.g.,
"FZRA". FZ shall not be coded with SH.
c. Precipitation. Up to three types of precipitation may be coded in
a single present weather group. They shall be coded in order of decreasing
dominance based on intensity.
(1) Drizzle shall be coded as DZ; rain shall be coded as RA;
snow shall be coded as SN; snow grains shall be coded as
SG; ice crystals shall be coded as IC; ice pellets shall
be coded as PE, hail shall be coded as GR, and small hail
and/or snow pellets shall be coded as GS.
(2) At automated stations, precipitation of unknown type shall be coded as
UP.
d. Obscuration.
(1) Mist shall be coded as BR; fog shall be coded as FG;
smoke shall be coded as FU; volcanic ash shall be coded as
VA; widespread dust shall be coded as DU; sand shall be
coded as SA; and haze shall be coded as HZ
(2) Shallow fog (MIFG), patches (of) fog (BCFG), and partial
fog (PRFG) may be coded with prevailing visibility of 7 statute
miles or greater.
(3) Spray shall be coded only as BLPY.
e. Other Weather Phenomena
(1) Well-developed dust/sand whirls shall be coded as PO; squalls
shall be coded as SQ; sandstorm shall be coded as SS;
and duststorm shall be coded as DS.
(2) Tornadoes and waterspouts shall be coded as +FC. Funnel clouds
shall be coded as FC.
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a. Sky condition shall be coded in the format, NsNsNshshshs, where
NsNsNs is the amount of sky cover and hshshs is the height
of the layer. There shall be no space between the amount of sky cover
and the height of the layer. Sky condition shall be coded in an ascending
order up to thefirst overcast layer. At mountain stations, if the layer
is below station level, the height of the layer shall be coded as ///.
b. Vertical visibility shall be coded in the format, VVhshshs, where
VV identifies an indefinite ceiling and hshshs is the vertical
visibility into the indefinite ceiling (see paragraphs 9.4.4, 9.4.7, and
9.5.5). There shall be no space between the group identifier and the vertical
visibility.
c. Clear skies shall be coded in the format, SKC or CLR, where
SKC is the abbreviation used by manual stations to indicate no
layers are present and CLR is the abbreviation used by automated
stations to indicate no layers are detected at or below 12,000 feet (see
paragraph 9.5.4).
Each layer shall be separated from other layers by a space. The sky cover for each layer reported shall
be coded by using the appropriate reportable contraction from Table 12-3. The report of clear skies (SKC
or CLR) are complete layer reports within themselves. The abbreviations FEW, SCT, BKN, and OVC
shall be followed, without a space, by the height of the layer.
| Reportable Contraction | Meaning | Summation Amount of Layer |
|---|---|---|
| VV | Vertical Visibility | 8/8 |
| SKC or CLR¹ | Clear | 0 |
| FEW² | Few | 1/8 - 2/8 |
| SCT | Scattered | 3/8 - 4/8 |
| BKN | Broken | 5/8 - 7/8 |
| OVC | Overcast | 8/8 |
1. The abbreviation CLR shall be used at automated stations when no layers at or below 12,000 feet are reported; the abbreviation SKC shall be used at manual stations when no layers are reported. 2. Any layer amount less than 1/8 is reported as FEW. |
||
| Range of Height Values (feet) | Reportable Increment (feet) |
|---|---|
| <=5,000 | To nearest 100 |
| >5,000 but <=10,000 | To nearest 500 |
| >10,000 | To nearest 1,000 |
At manual stations, cumulonimbus (CB) or towering cumulus (TCU) shall be appended to the associated layer. For example, a scattered layer of towering cumulus at 1,500 feet would be coded "SCT015TCU" and would be followed by a space if there were additional higher layers to code.
Temperature/Dew Point Group (T'T'/T'dT'd). The standards for observing and reporting temperature and dew point are given in Chapter 10. The temperature shall be separated from the dew point with a solidus "/".
The temperature and dew point shall be coded as two digits rounded to the nearest whole degree Celsius (see paragraph 2.6.3). For example, a temperature of 0.3C would be coded as "00". Sub-zero temperatures and dew points shall be prefixed with an M. For example, a temperature of 4C with a dew point of -2C would be coded as "04/M02"; a temperature of -0.5C would be coded as "M00".
If the temperature is not available, the entire temperature/dew point group shall not be coded. If the dew point is not available, the temperature shall be coded followed by a solidus "/" and no entry made for dew point. For example, a temperature of 1.5C and a missing dew point would be coded as "02/".
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Altimeter (APHPHPHPH). The standards for observing and reporting altimeter are described
in Chapter 11.
The altimeter group always starts with an A (the international indicator for altimeter in inches of mercury). The altimeter shall be coded as a four digit group immediately following the A using the tens, units, tenths, and hundredths of inches of mercury. The decimal point is not coded.
Remarks (RMK)
Remarks shall be included in all METAR and SPECI, if appropriate.
Remarks shall be separated from the body of the report by a space and the contraction RMK. If there are no remarks, the contraction RMK is not required.
METAR/SPECI remarks fall into 2 categories: (1) Automated, Manual, and Plain Language (see paragraph 12.7.1), and (2) Additive and Maintenance Data (see paragraph 12.7.2).
Remarks shall be made in accordance with the following:
a. Where plain language is called for, authorized contractions,
abbreviations, and symbols should be used to conserve time and
space. However, in no case should an essential remark, of which
the observer is aware, be omitted for the lack of readily available
contractions. In such cases, the only requirement is that the
remark be clear. For a detailed list of authorized contractions,
see FAA Order 7340 Series, Contractions.
b. Time entries shall be made in minutes past the hour if the time
reported occurs during the same hour the observation is taken.
Hours and minutes shall be used if the hour is different, or this
Handbook prescribes the use of the hour and minutes.
c. Present weather coded in the body of the report as VC may
be further described, i.e., direction from the station, if known.
Weather phenomena beyond 10 statute miles of the point(s) of
observation shall be coded as distant (DSNT) followed by the
direction from the station. For example, precipitation of unknown
intensity within 10 statute miles east of the station would be coded
as "VCSH E"; lightning 25 statute miles west of the station would be
coded as "LTG DSNT W".
d. Distance remarks shall be statute miles except for automated lightning
remarks which are in nautical miles.
e. Movement of clouds or weather, if known, shall be coded with respect
to the direction toward which the phenomena is moving. For example,
a thunderstorm moving toward the northeast would be coded as "TS MOV NE".
f. Directions shall use the eight points of the compass coded in a
clockwise order.
g. Insofar as possible, remarks shall be entered in the order they are
presented in the following paragraphs.
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a. Volcanic Eruptions (Plain Language). Volcanic eruptions shall be coded.
The remark shall be plain language and contain the following, if known:
(1) Name of volcano.
(2) Latitude and longitude or the direction and the approximate
distance from the station.
(3) Date/Time (UTC) of the eruption.
(4) Size description, approximate height, and direction of
movement of the ash cloud.
(5) Any other pertinent data about the eruption.
For example, a remark on a volcanic eruption would look like
the following:
MT. AUGUSTINE VOLCANO 70 MILES SW ERUPTED 231505 LARGE ASH CLOUD
EXTENDING TO APRX 30000 FEET MOVING NE.
Pre-eruption volcanic activity shall not be coded. Pre-eruption
refers to unusual and/or increasing volcanic activity which
could presage a volcanic eruption.
b. Funnel Cloud (Tornadic activity_B/E(hh)mm_LOC/DIR_(MOV)). At
manual stations, tornadoes, funnel clouds, or waterspouts shall be
coded in the format, Tornadic activity_B/E(hh)mm_LOC/DIR_(MOV),
where TORNADO, FUNNEL CLOUD, orWATERSPOUT identifies the
specific tornadic activity, B/E denotes the beginning and/or
ending time, (hh)mm is the time of occurrence (only the minutes
are required if the hour can be inferred from the report time), LOC/DIR
is the location and/or direction of the phenomena from the station,
and MOV is the movement, if known (see paragraphs 8.3.3.c, 8.5.3.c,
and 8.5.5.b). Tornadic activity shall be coded as the first remark after
the "RMK" entry. For example, "TORNADO B13 6 NE" would indicate that a
tornado, which began at 13 minutes past the hour, was 6 statute miles
northeast of the station.
c. Type of Automated Station (AO1 or AO2). AO1 or AO2
shall be coded in all METAR/SPECI from automated stations. Automated
stations without a precipitation discriminator shall be identified as
AO1; automated station with a precipitation discriminator shall
be identified as AO2.
d. Peak Wind (PK_WND_dddff(f)/(hh)mm). The peak wind shall be coded
in the format,PK_WND dddff(f)/(hh)mm of the next METAR, where PK_WND
is the remark identifier, ddd is the direction of the peak wind,
ff(f) is the peak wind speed since the last METAR, and (hh)mm is
the time of occurrence (only the minutes are required if the hour can be
inferred from the report time) (see paragraphs 5.4.5 and 5.5.5). There
shall be a space between the two elements of the remark identifier and the
wind direction/speed group; a solidus "/" (without spaces) shall
separate the wind direction/speed group and the time. For example, a peak
wind of 45 knots from 280 degrees that occurred at 15 minutes past the hour
would be coded "PK WND 28045/15".
e. Wind Shift (WSHFT_(hh)mm). A wind shift shall be coded in the format,
WSHFT_(hh)mm, where WSHFT is the remark identifier and (hh)mm
is the time the wind shift began (only the minutes are required if the hour
can be inferred from the report time) (see paragraphs 5.4.6 and 5.5.6). The
contraction FROPA may be entered following the time if it is reasonably
certain that the wind shift was the result of a frontal passage. There shall
be a space between the remark identifier and the time and, if applicable,
between the time and the frontal passage contraction. For example, a remark
reporting a wind shift accompanied by a frontal passage that began at
30 minutes after the hour would be coded as "WSHFT 30 FROPA".
f. Tower or Surface Visibility (TWR_VIS_vvvvv or SFC_VIS_vvvvv).
Tower visibility or surface visibility (see paragraphs 6.5.4 and 6.5.5)
shall be coded in the formats, TWR_VIS_vvvvv or SFC_VIS_vvvvv,
respectively, where vvvvv is the observed tower/surface
visibility value. A space shall be coded between each of the remark
elements. For example, the control tower visibility of 1 1/2 statute
miles would be coded "TWR VIS 1 1/2".
g. Variable Prevailing Visibility (VIS_vnvnvnvnvnVvxvxvxvxvx).
Variable prevailing visibility shall be coded in the format
VIS_vnvnvnvnvnVvxvxvxvxvx, where VIS is the remark
identifier, vnvnvnvnvn is the lowest visibility evaluated,
V denotes variability between two values, and vxvxvxvxvx
is the highest visibility evaluated. There shall be one space following
the remark identifier; no spaces between the letter V and the
lowest/highest values. For example, a visibility that was varying
between 1/2 and 2 statute miles would be coded "VIS 1/2V2" (see
paragraphs 6.4.5 and 6.5.3).
h. Sector Visibility (VIS_[DIR]_vvvvv) [Plain Language]. The
sector visibility shall be coded in the format, VIS_[DIR]_vvvvv,
where VIS is the remark identifier, [DIR] defines
the sector to 8 points of the compass, and vvvvv is the sector
visibility in statute miles, using the appropriate set of values in
Table 12-1 (see paragraphs 6.4.6 and 6.5.7). For example, a visibility
of 2 1/2 statute miles in the northeastern octant would be
coded "VIS NE 2 1/2".
i. Visibility At Second Location (VIS_vvvvv_[LOC]). At designated
automated stations, the visibility at a second location shall be coded
in the format VIS_vvvvv_[LOC], where VIS is the remark
identifier, vvvvv is the measured visibility value, and [LOC]
is the specific location of the visibility sensor(s) at the station (see
paragraph 6.5.6). This remark shall only be generated when the condition
is lower than that contained in the body of the report. For example, a
visibility of 2 1/2 statute miles measured by a second sensor located at
runway 11 would be coded "VIS 2 1/2 RWY11".
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j. Lightning (Frequency_LTG(type)_[LOC]).
(1) When lightning is observed at a manual station, the frequency,
type of lightning, and location shall be reported. The remark
shall be coded in the format Frequency_LTG(type)_[LOC].
The contractions for the type and frequency of lightning shall
be based on Table 12-5. The location and direction shall be coded
in accordance with paragraph 12.7.c. For example, "OCNL LTGICCG OHD",
"FRQ LTG VC", or "LTG DSNT W".
(2) When lightning is detected by an automated system:
(a) Within 5 nautical miles of the Airport Location Point (ALP),
it will be reported as TS in the body of the report
with no remark;
(b) Between 5 and 10 nautical miles of the ALP, it will be reported
as VCTS in the body of the report with no remark;
(c) Beyond 10 but less than 30 nautical miles of the ALP, it will
be reported in remarks only as LTG DSNT followed by the
direction from the ALP.
| Type of Lightning | ||
|---|---|---|
| Type | Contraction | Definition |
| Cloud-ground | CG | Lightning occurring between cloud and ground. |
| In-cloud | IC | Lightning which takes place within the cloud. |
| Cloud-cloud | CC | Streaks of lightning reaching from one cloud to another. |
| Cloud-air | CA | Streaks of lightning which pass from a cloud to air, but do not strike the ground. |
| Frequency of Lightning | ||
| Frequency | Contraction | Definition |
| Occasional | OCNL | Less than 1 flash/minute. |
| Frequent | FRQ | About 1 to 6 flashes/minute. |
| Continuous | CONS | More than 6 flashes/minute. |
k. Beginning and Ending of Precipitation (w'w'B(hh)mmE(hh)mm).
At designated stations, the beginning and ending of precipitation
shall be coded in the format, w'w'B(hh)mmE(hh)mm, where w'w'
is the type of precipitation, B denotes the beginning, E
denotes the ending, and (hh)mm is the time of occurrence (only the
minutes are required if the hour can be inferred from the report time)
(see paragraph 8.5.5.a). There shall be no spaces between the elements.
The coded remarks are not required in SPECI and should be reported in
the next METAR. Intensity qualifiers shall not be coded. For example,
if rain began at 0005, ended at 0030, and snow began at 0020, and ended
at 0055, the remarks would be coded "RAB05E30SNB20E55". If the precipitation
were showery, the remark would be coded "SHRAB05E30SHSNB20E55".
l. Beginning and Ending of Thunderstorms (TSB(hh)mmE(hh)mm). The
beginning and ending of thunderstorm(s) shall be coded in the format,
TSB(hh)mmE(hh)mm, where TS indicates thunderstorm, B
denotes the beginning, E denotes the ending, and (hh)mm
is the time of occurrence (only the minutes are required if the hour can be
inferred from the report time) (see paragraph 8.5.4). There shall be no
spaces between the elements. For example, if a thunderstorm began at 0159
and ended at 0230, the remark would be coded "TSB0159E30".
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m. Thunderstorm Location (TS_LOC_(MOV_DIR)) [Plain Language].
Thunderstorm(s) shall be coded in the format, TS_LOC_(MOV_DIR),
where TS identifies the thunderstorm activity, LOC is the
location of the thunderstorm(s) from the station, and MOV_DIR is
the movement with direction, if known (see paragraph 8.4.1.b(5) and 8.5.4).
For example, a thunderstorm southeast of the station and moving toward the
northeast would be coded "TS SE MOV NE".
n. Hailstone Size (GR_[size]) [Plain Language]. At designated
stations, the hailstone size shall be coded in the format, GR_[size],
where GR is the remark identifier and [size] is the
diameter of the largest hailstone. The hailstone size shall be coded in
1/4 inch increments (see paragraph 8.5.1.c(8)). For example, "GR 1 3/4"
would indicate that the largest hailstones were 1 3/4 inches in diameter.
If GS is coded in the body of the report, no hailstone size remark
is required.
o. Virga (VIRGA_(DIR)) [Plain Language]. Virga shall be coded
in the format, VIRGA_(DIR), where VIRGA is the remark
identifier and DIR is the direction from the station. The
direction of the phenomena from the station is optional, e.g., "VIRGA"
or "VIRGA SW".
p. Variable Ceiling Height (CIG_hnhnhnVhxhxhx). The variable
ceiling height shall be coded in the format, CIG_hnhnhnVhxhxhx,
where CIG is the remark identifier, hnhnhn is the
lowest ceiling height evaluated, V denotes variability between
two values, and hxhxhx is the highest ceiling height evaluated
(see paragraph 9.5.7 and Table 9-1). There shall be one space
following the remark identifier; no spaces between the
letter V and the lowest/highest ceiling values. For example,
"CIG 005V010" would indicate a ceiling that was varying between 500
and 1,000 feet.
q. Obscurations (w'w'_[NsNsNs]hshshs). [Plain Language]
Obscurations (surface-based or aloft) shall be coded in the format,
w'w'_[NsNsNs]hshshs, where w'w' is the weather causing
the obscuration at the surface or aloft, NsNsNs is the applicable sky
cover amount of the obscuration aloft (FEW, SCT, BKN, OVC) or at the
surface (FEW, SCT, BKN), and hshshs is the applicable height
(see paragraphs 9.4.3 and 9.5.6). Surface-based obscurations shall have
a height of "000". There shall be a space separating the weather
causing the obscuration and the sky cover amount; there shall be no space
between the sky cover amount and the height. For example, fog hiding
3-4 oktas of the sky would be coded "FG SCT000"; a broken layer at 2,000 feet
composed of smoke would be coded "FU BKN020".
r. Variable Sky Condition (NsNsNs(hshshs)_V_NsNsNs). [Plain Language]
The variable sky condition remark shall be coded in the format,
NsNsNs(hshshs)_V_NsNsNs, where NsNsNs(hshshs) and NsNsNs
identifies the two operationally significant sky conditions and V denotes
the variability between the two ranges (see paragraphs 9.4.2.d and 9.5.9).
If there are several layers with the same sky condition amount, the layer
height (hshshs) of the variable layer shall be coded. For example,
a cloud layer at 1,400 feet that is varying between broken and overcast would
be coded "BKN014 V OVC".
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s. Significant Cloud Types [Plain Language]. The significant cloud
type remark shall be coded in all reports in the following manner (see
paragraphs 9.4.6 and 9.5.10):
(1) Cumulonimbus or Cumulonimbus Mammatus (CB or CBMAM_LOC_(MOV_DIR).
Cumulonimbus or cumulonimbus mammatus, as appropriate, (for which no
thunderstorm is being reported) shall be coded in the format, CB or
CBMAM_LOC_(MOV_DIR), where CB or CBMAM is the cloud
type, LOC is the direction from the station, and MOV_DIR is
the movement with direction (if known). The cloud type, location, movement,
and direction entries shall be separated from each other with a space.
For example, a CB up to 10 statute miles west of the station moving
toward the east would be coded "CB W MOV E". If the CB was more than
10 statute miles to the west, the remark would be coded "CB DSNT W".
(2) Towering cumulus (TCU_[DIR]). Towering cumulus clouds shall be
coded in the format, TCU_[DIR], where TCU is the cloud
type and DIR is the direction from the station. The cloud type
and direction entries shall be separated by a space. For example, a
towering cumulus cloud up to 10 statute miles west of the station would
be coded "TCU W".
(3) Altocumulus castellanus (ACC_[DIR]). Altocumulus castellanus
shall be coded in the format, ACC_[DIR], where ACC is
the cloud type and DIR is the direction from the station. The
cloud type and direction entries shall be separated by a space. For
example, an altocumulus cloud 5 to 10 statute miles northwest of the
station would be coded "ACC NW".
(4) Standing lenticular or Rotor clouds (CLD_[DIR]). Stratocumulus
(SCSL), altocumulus (ACSL), or cirrocumulus (CCSL), or rotor clouds shall
be coded in the format, CLD_[DIR], where CLD is the cloud
type and DIR is the direction from the station. The cloud type
and direction entries shall be separated by a space. For example,
altocumulus standing lenticular clouds observed southwest through west
of the station would be coded "ACSL SW-W"; an apparent rotor cloud 5 to
10 statute miles northeast of the station would be coded "APRNT ROTOR CLD
NE"; and cirrocumulus clouds south of the station would be coded "CCSL S".
t. Ceiling Height at Second Location (CIG_hhh_[LOC]). At
designated stations, the ceiling height at a second location shall be
coded in the format, CIG_hhh_[LOC], where CIG is the remark
identifier, hhh is the measured height of the ceiling, and [LOC]
is the specific location of the ceilometer(s) at the station (see paragraph
9.5.8). This remark shall only be generated when the ceiling is lower than
that contained in the body of the report. For example, if the ceiling
measured by a second sensor located at runway 11 is broken at 200 feet,
the remark would be "CIG 002RWY11".
u. Pressure Rising or Falling Rapidly (PRESRR/PRESFR). At designated
stations, when the pressure is rising or falling rapidly at the time of
observation (see paragraphs 11.4.6 and 11.5.5), the remark PRESRR
(pressure rising rapidly) or PRESFR (pressure falling rapidly) shall
be included in the report.
v. Sea-Level Pressure (SLPppp). At designated stations, the sea-level
pressure shall be coded in the format SLPppp, where SLP is
the remark identifier and ppp is the sea-level pressure in
hectopascals (see paragraphs 11.4.4 and 11.5.4). For example, a sea-level
pressure of 998.2 hectopascals would be coded as "SLP982". For a METAR, if
sea-level pressure is not available, it is coded as "SLPNO".
w. Aircraft Mishap (ACFT_MSHP) [Plain Language]. If a report is
taken to document weather conditions when notified of an aircraft mishap,
the remark ACFT_MSHP shall be coded in the report but not transmitted.
The act of non-transmission shall be indicated by enclosing the remark in
parentheses in the record, i.e., "(ACFT MSHP)".
x. No SPECI Reports Taken (NOSPECI) [Plain Language]. At manual
stations where SPECI's are not taken, the remark NOSPECI shall
be coded to indicate that no changes in weather conditions will be
reported until the next METAR.
y. Snow Increasing Rapidly (SNINCR_[inches-hour/inches on ground]).
At designated stations, the snow increasing rapidly remark shall be
reported, in the next METAR, whenever the snow depth increases by 1 inch
or more in the past hour. The remark shall be coded in the format,
SNINCR [inches-hour/inches on ground], where SNINCR is the
remark indicator, inches-hour is the depth increase in the past hour,
and inches on ground is the total depth of snow on the ground at
the time of the report. The depth increase in the past hour and the total
depth on the ground are separated from each other by a solidus "/".
For example, a snow depth increase of 2 inches in the past hour with a
total depth on the ground of 10 inches would be coded "SNINCR 2/10".
z. Other Significant Information [Plain Language]. Agencies may
add to a report other information significant to their operations, such
as information on fog dispersal operations, runway conditions, "FIRST"
or "LAST" report from station, etc.
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a. Precipitation
(1) Amount of Precipitation. The amount of liquid precipitation
shall be coded as the depth of precipitation that accumulates in an
exposed vessel during the time period being evaluated. The amount
of freezing or frozen precipitation shall be the water equivalent of
the solid precipitation accumulated during the appropriate time period.
(2) Units of Measure for Precipitation. Precipitation measurements
shall be in inches, tenths of inches, or hundredths of inches
depending on the precipitation being measured (see Table 12-6).
| Type of Measurement | Unit of Measure |
|---|---|
| Liquid Precipitation | 0.01 inch |
| Water Equivalent of Solid Precipitation | 0.01 inch |
| Solid Precipitation | 0.1 inch |
| Snow Depth | 1.0 inch |
(3) Depth of Freezing or Frozen Precipitation. The depth
of freezing and/or frozen precipitation shall be the actual
vertical depth of the precipitation accumulated on a horizontal
surface during the appropriate time period (see paragraphs 12.7.2.a(3)(b)
and 12.7.2.a(3)(c). If snow falls, melts, and refreezes, the
depth of ice formed shall be included in the measurement.
(a) Hourly Precipitation Amount (Prrrr). At designated
automated stations, the hourly precipitation amount shall
be coded in the format, Prrrr, where P is the
group indicator and rrrr is the water equivalent of all
precipitation that has occurred since the last METAR (see
paragraph 12.7.2.a(1)). The amount shall be coded in
hundredths of an inch. For example, "P0009" would indicate
9/100 of an inch of precipitation fell in the past hour; "P0000"
would indicate that less than 1/100 of an inch of precipitation
fell in the past hour.
The group shall be omitted if no precipitation occurred since the
last METAR.
(b) 3- and 6-Hour Precipitation Amount (6RRRR). At designated
stations, the 3- and 6-hourly precipitation group shall be coded
in the format, 6RRRR, where 6 is the group indicator
and RRRR is the amount of precipitation. The amount of
precipitation (water equivalent) accumulated in the past 3 hours
shall be reported in the 3-hourly report; the amount accumulated
in the past 6 hours shall be reported in the 6-hourly report. The
amount of precipitation shall be coded in inches, using the tens,
units, tenths and hundredths digits of the amount. When an
indeterminable amount of precipitation has occurred during the
period, RRRR shall be coded 6////. For example, 2.17 inches
of precipitation would be coded "60217". A trace shall be
coded "60000".
(c) 24-Hour Precipitation Amount (7R24R24R24R24). At
designated stations, the 24-hour precipitation amount shall be
coded in the format, 7R24R24R24R24, where 7 is the
group indicator and R24R24R24R24 is the 24-hour precipitation
amount. The 24-hour precipitation amount shall be included in the
1200 UTC (or other agency designated time) report whenever more
than a trace of precipitation (water equivalent) has fallen in the
preceding 24 hours. The amount of precipitation shall be coded by
using the tens, units, tenths, and hundredths of inches (water
equivalent) for the 24-hour period. If more than a trace (water
equivalent) has occurred and the amount cannot be determined, the
group shall be coded 7////. For example, 1.25 inches of
precipitation (water equivalent) in the past 24 hours shall be
coded "70125".
(d) Snow Depth on Ground (4/sss). At designated stations,
the total snow depth on the ground group shall be coded in the
0000 and 1200 UTC observation whenever there is more than a trace
of snow on the ground. It shall be coded in the 0600 and 1800 UTC
observation if there is more than a trace of snow on the ground
and more than a trace of precipitation (water equivalent) has
occurred within the past 6 hours. The remark shall be coded in
the format, 4/sss, where 4/ is the group indicator
and sss is the snow depth in whole inches using three digits.
For example, a snow depth of 21 inches shall be coded as "4/021".
(e) Water Equivalent of Snow on Ground (933RRR). At
designated stations, the water equivalent of snow on the ground
shall be coded each day, in the 1800 UTC report, if the average
snow depth is 2 inches or more. Theremark shall be coded in the
format, 933RRR, where 933 is the group indicator
and RRR is the water equivalent of snow, i.e., snow, snow
pellets, snow grains, ice pellets, ice crystals, and hail, on
the ground. The water equivalent shall be coded in tens, units,
and tenths of inches, using three digits. If the water equivalent
of snow consists entirely of hail, the group shall not be coded.
A water equivalent of 3.6 inches of snow would be coded as "933036";
a water equivalent of 12.5 would be coded as "933125".
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b. Cloud Types (8/CLCMCH). At designated stations, the group,
8/CLCMCH, shall be reported and coded in 3- and 6-hourly reports
when clouds are observed. The predominant low cloud (CL), middle
cloud (CM), and high cloud (CH), shall be identified in
accordance with the WMO International Cloud Atlas, Volumes I and II,
or the WMO Abridged International Cloud Atlas or agency observing
aids for cloud identification. A 0 shall be coded for the low,
middle, or high cloud type if no cloud is present in that classification.
A solidus "/" shall be coded for layers above an overcast. If no
clouds are observed due to clear skies, the cloud type group shall not
be coded. For example, a report of "8/6//" would indicate an overcast
layer of stratus clouds; a report of "8/903" would indicate cumulonimbus
type low clouds, no middle clouds, and dense cirrus high clouds.
c. Duration of Sunshine (98mmm). The duration of sunshine that
occurred the previous calendar day shall be coded in the 0800 UTC report.
If the station is closed at 0800 UTC, the group shall be coded in the
first 6-hourly METAR after the station opens. The duration of sunshine
shall be coded in the format, 98mmm, where 98 is the group
indicator and mmm is the total minutes of sunshine. The minutes
of sunshine shall be coded by using the hundreds, tens, and units digits.
For example, 96 minutes of sunshine would be coded "98096". If no
sunshine occurred, the group would be coded "98000".
d. Hourly Temperature and Dew Point (TsnT'T'T'snT'dT'dT'd). At
designated stations, the hourly temperature and dew point group shall
be coded to the tenth of a degree Celsius in the format, TsnT'T'T'snT'dT'dT'd,
where T is the group indicator, sn is the sign of the temperature,
T'T'T' is the temperature, and T'dT'dT'd is the dew point
(see paragraphs 10.5.1 and 10.5.3). The sign of the temperature and
dew point shall be coded as 1 if the value is below 0°C and 0 if the value
is 0°C or higher. The temperature and dew point shall be reported
in tens, units, and tenths of degrees Celsius. There shall be no spaces
between the entries. For example, a temperature of 2.6°C and dew
point of -1.5°C would be reported in the body of the report as
"03/M01" and the TsnT'T'T'snT'dT'dT'd group as "T00261015". If
dew point is missing report the temperature; if the temperature is missing
do not report the temperature/dew point group.
e. 6-Hourly Maximum Temperature (1snTxTxTx). At designated
stations, the 6-hourly maximum temperature group shall be coded in the
format, 1snTxTxTx, where 1 is the group indicator, sn
is the sign of the temperature, TxTxTx is the maximum temperature
in tenths of degrees Celsius using three digits (see paragraphs 10.4.4,
10.5.2, and 10.5.3). The sign of the maximum temperature shall be coded
as 1 if the maximum temperature is below 0°C and 0 if the maximum
temperature is 0°C or higher. For example, a maximum temperature
of -2.1°C would be coded "11021"; 14.2°C would be coded "10142".
f. 6-Hourly Minimum Temperature (2snTnTnTn). At designated stations,
the 6-hourly minimum temperature group shall be coded in the format,
2snTnTnTn, where 2 is the group indicator, sn is the
sign of the temperature, and TnTnTn is the minimum temperature in
tenths of degrees Celsius using three digits (see paragraphs 10.4.4,
10.5.2, and 10.5.3). The sign of the minimum temperature shall be coded
as 1 if the minimum temperature is below 0°C and 0 if the minimum
temperature is 0°C or higher. For example, a minimum temperature
of -0.1°C would be coded "21001"; 1.2°C would be coded "20012".
g. 24-Hour Maximum and Minimum Temperature (4snTxTxTxsnTnTnTn). At
designated stations, the 24-hour maximum temperature and the 24-hour
minimum temperature shall be coded in the format, 4snTxTxTxsnTnTnTn,
where 4 is the group indicator, sn is the sign of the
temperature, TxTxTx is the maximum 24-hour temperature, and TnTnTn
is the 24-hour minimum temperature (see paragraphs 10.4.4, 10.5.2, and
10.5.3). TxTxTx and TnTnTn shall be coded in tenths of
degrees Celsius using three digits. The sign of the maximum or minimum
temperature shall be coded as 1 if it is below 0°C and 0 if it
is 0°C or higher. For example, a 24-hour maximum temperature of
10.0°C and a 24-hour minimum temperature of -1.5°C would be coded
"401001015"; a 24-hour maximum temperature of 11.2°C and a 24-hour
minimum temperature of 8.4C would be coded as"401120084".
h. 3-Hourly Pressure Tendency (5appp). At designated stations, the
3-hourly pressure tendency group shall be coded in the format, 5appp,
where 5 is the group indicator, a is the character of
pressure change over the past 3 hours (see Table 12-7), and ppp
is the amount of barometric change in tenths of hectopascals (see Table 12-8).
The amount of barometric change shall be coded using the tens, units, and
tenths digits (see paragraphs 11.4.7 and 11.5.4). For example, a steady
increase of 3.2 hectopascals in the past three hours would be coded "52032".
| Primary Requirement |
Description | Code Figure |
|---|---|---|
| Atmospheric pressure now higher than 3 hours ago. |
Increasing, then decreasing. | 0 |
| Increasing, then steady, or increasing then increasing more slowly. |
1 | |
| Increasing steadily or unsteadily. | 2 | |
| Decreasing or steady, then increasing; or increasing then increasing more rapidly. |
3 | |
| Atmospheric pressure now same as 3 hours ago. |
Increasing, then decreasing. | 0 |
| Steady | 4 | |
| Decreasing then increasing. | 5 | |
| Atmospheric pressure now lower than 3 hours ago. |
Decreasing, then increasing. | 5 |
| Decreasing, then steady, or decreasing then decreasing more slowly. |
6 | |
| Decreasing steadily or unsteadily. | 7 | |
| Steady or increasing, then decreasing; or decreasing then decreasing more rapidly. |
8 |
| Amount of Barometric Change (Rise or Fall) in the Past 3 hours "ppp" | ||||||||
|---|---|---|---|---|---|---|---|---|
| Code Figure |
Inches of Mercury |
Hectopascals | Code Figure |
Inches of Mercury |
Hectopascals | Code Figure |
Inches of Mercury |
Hectopascals |
| 000 002 003 005 007 008 010 012 014 015 017 019 020 022 024 025 027 029 030 032 034 036 037 039 041 042 044 046 047 049 051 052 054 056 058 059 061 063 064 066 |
0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.040 0.045 0.050 0.055 0.060 0.065 0.070 0.075 0.080 0.085 0.090 0.095 0.100 0.105 0.110 0.115 0.120 0.125 0.130 0.135 0.140 0.145 0.150 0.155 0.160 0.165 0.170 0.175 0.180 0.185 0.190 0.195 |
0.0 0.2 0.3 0.5 0.7 0.8 1.0 1.2 1.4 1.5 1.7 1.9 2.0 2.2 2.4 2.5 2.7 2.9 3.0 3.2 3.4 3.6 3.7 3.9 4.1 4.2 4.4 4.6 4.7 4.9 5.1 5.2 5.4 5.6 5.8 5.9 6.1 6.3 6.4 6.6 |
068 069 071 073 075 076 078 080 081 083 085 086 088 090 091 093 095 097 098 100 102 103 105 107 108 110 112 113 115 117 119 120 122 124 125 127 129 130 132 134 |
0.200 0.205 0.210 0.215 0.220 0.225 0.230 0.235 0.240 0.245 0.250 0.255 0.260 0.265 0.270 0.275 0.280 0.285 0.290 0.295 0.300 0.305 0.310 0.315 0.320 0.325 0.330 0.335 0.340 0.345 0.350 0.355 0.360 0.365 0.370 0.375 0.380 0.385 0.390 0.395 |
6.8 6.9 7.1 7.3 7.5 7.6 7.8 8.0 8.1 8.3 8.5 8.6 8.8 9.0 9.1 9.3 9.5 9.7 9.8 10.0 10.2 10.3 10.5 10.7 10.8 11.0 11.2 11.3 11.5 11.7 11.9 12.0 12.2 12.4 12.5 12.7 12.9 13.0 13.2 13.4 |
135 137 139 141 142 144 146 147 149 151 152 154 156 157 159 161 163 164 166 168 169 171 173 174 176 178 179 181 183 185 186 188 190 191 193 195 196 198 200 201 |
0.400 0.405 0.410 0.415 0.420 0.425 0.430 0.435 0.440 0.445 0.450 0.455 0.460 0.465 0.470 0.475 0.480 0.485 0.490 0.495 0.500 0.505 0.510 0.515 0.520 0.525 0.530 0.535 0.540 0.545 0.550 0.555 0.560 0.565 0.570 0.575 0.580 0.585 0.590 0.595 |
13.5 13.7 13.9 14.1 14.2 14.4 14.6 14.7 14.9 15.1 15.2 15.4 15.6 15.7 15.9 16.1 16.3 16.4 16.6 16.8 16.9 17.1 17.3 17.4 17.6 17.8 17.9 18.1 18.3 18.5 18.6 18.8 19.0 19.1 19.3 19.5 19.6 19.8 20.0 20.1 |
i. Sensor Status Indicators. Sensor status indicators should be
reported as indicated below:
(1) if the Runway Visual Range should be reported but is missing,
RVRNO shall be coded.
(2) when automated stations are equipped with a present weather
identifier and that sensor is not operating, the remark PWINO
shall be coded.
(3) when automated stations are equipped with a tipping bucket
rain gauge and that sensor is not operating, PNO shall
be coded.
(4) when automated stations are equipped with a freezing rain
sensor and that sensor is not operating, the remark FZRANO
shall be coded.
(5) when automated stations are equipped with a lightning detection
system and that sensor is not operating, the remark TSNO
shall be coded.
(6) when automated stations are equipped with a secondary visibility
sensor and that sensor is not operating, the remark VISNO_LOC
shall be coded.
(7) when automated stations are equipped with a secondary ceiling height
indicator and that sensor is not operating, the remark CHINO_LOC
shall be coded.
j. Maintenance Indicator. A maintenance indicator sign, $,
shall be coded when an automated system detects that maintenance is
needed on the system.
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FFAA. Radar Observation indicator.
a. FF. Land based radar, GG. Sea based radar.
b. AA. Tropical Cyclone information, BB. significant weather information.
DTG. Date Time Group. DDHHm.
a. DD. Day of the month in two digits.
b. HH. Zulu hour.
c. m. Minute tens digit (09=1 for 10 minutes, 22=2 for 20 minutes, etc)
Station. IIiii. WMO block and station number.
a. II. WMO block.
b. iii. Station number.
Lat. 4WvLaLaLa. Latitude group.
a. 4. Indicator for the group.
b. Wv. Wave length of radar.
c. LaLaLa Latitude to the nearest tenth of a degree.
Long. QcLoLoLoLo. Longitude group.
a. Qc. Quadrant of the globe
1 = N and E
3 = S and E
5 = S and W
7 = N and W
b. LoLoLoLo. Longitude to the nearest tenth of a degree.
Char. Coded characteristics of the eye of the system.
Ac--Accuracy of the position of the center or the eye of the
tropical cyclone.
Code
Fig.
1 Eye visible on radar scope, accuracy good (within 10km).
2 Eye visible on radar scope, accuracy fair (within 30 km).
3 Eye visible on radar scope, accuracy poor (within 50 km).
4 Position of the center within the area covered by the radar scope,
determination by means of the spiral-band overlay, accuracy good
(within 10km).
5 Position of the center within the area covered by the radar scope,
determination by means of the spiral-band overlay, accuracy fair
(within 30km).
6 Position of the center within the area covered by the radar scope,
determination by means of the spiral-band overlay, accuracy poor
(within 50km).
7 Position of the center outside the area covered by the radar scope,
extrapolation by means of the spiral-band overlay.
/ Accuracy undetermined.
Sc--Shape and definition of the eye of the tropical cyclone.
Code
Fig.
0 Circular.
1 Elliptical-the minor axis at least 3/4 the length of the major axis.
2 Elliptical-the minor axis is less than 3/4 the length of the major axis.
3 Apparent double eye.
4 Other shape.
5 Ill defined.
/ Undetermined.
Wc--Diameter or length of axis of the eye of the tropical cyclone.
Code
Fig.
0 Less than 5 km.
1 5 to less than 10 km.
2 10 to less than 15 km.
3 15 to less than 20 km.
4 20 to less than 25 km.
5 25 to less than 30 km.
6 30 to less than 35 km.
7 35 to less than 40 km.
8 40 to less than 50 km.
9 50 km and greater.
/ Undetermined.
ac--Change in character of the eye during the past 30 minutes preceding
the time of observation.
Code
Fig.
0 Eye has first become visible during the past 30 minutes.
1 No significant change in characteristics or size of the eye.
2 Eye has become smaller with no other significant change in characteristics.
3 Eye has become larger with no other significant change in characterisitcs.
4 Eye has become less distinct with no significant change in size.
5 Eye has become less distinct and decreased in size.
6 Eye has become less distinct and increased in size.
7 Eye has become more distinct with no significant change in size.
8 Eye has become more distinct and decreased in size.
9 Eye has become more distinct and increased in size.
/ Change in character and size of eye cannot be determined.
rt--Distance between the end of the outermost spiral band and the
center of the tropical cyclone.
Code
Fig.
0 0 to less than 100 km.
1 100 to less than 200 km.
2 200 to less than 300 km.
3 300 to less than 400 km.
4 400 to less than 500 km.
5 500 to less than 600 km.
6 600 to less than 800 km.
7 800 km or more.
/ Doubtful or undetermined.
Mvmnt. tedsdsfsfs. Movement of the system.
a. te. Time interval for which the system has been evaluated.
b. dsds. The direction in tens of degrees toward which the system is moving.
c. fsfs. The speed in knots at which the system is moving.
Top of PageSid...Storm Identifier.
Stnam...Storm Name
Dtg...Date. 01 is the Year 2001, 11 is the Month
November, and 27 is the day of the month.
HHmm...Hours and Minutes of the observation.
Lat...Latitude to the nearest tenth of a degree.
Long...Longitude to the nearest tenth of a degree.
Dir...Direction of movement.
Sm/s...Speed of movement in meters per second.
ChPa...Central Pressure in Hectopascals- 990 (hPa).
OhPa...Pressure of the outermost closed
isobar in Hectopascals- 1008 (hPa)
AUSTRALIAN TROPICAL OBSERVATION CODE
Rout...Radius of outermost closed isobar in Kilometers: 0450 (450km)
Max...Maximum Wind in meters per second: 20(m/s)
Rad...Radius of maximum wind in kilometers: 200 (km)
30NE...Radius of 15m/s (30knot) winds to the NE
30SE...Radius of 15m/s (30 knot) winds to the SE
30SW...Radius of 15m/s (30 knot) winds to the SW
30NW...Radius of 15m/s (30 knot) winds to the NW
SD...Storm Depth: D
(S=shallow<700hPa; M=medium 200-400hPa; D=Deep(>400hPa)
PART ALPHA (A)
XXAA Identifier for a temp drop codeYYGGId Identifier: YY Date Group Identifier: GG Time Group Identifier: Id - The highest mandatory level for which wind is available LATTITUDE: 99LaLaLa Identifier: 99 Indicator for data on position follows Identifier: LaLaLa Latitude in tenths of degrees LONGITUDE: QcLoLoLoLoc The octant of the globe Identifier: LoLoLoLo Longitude in tenths of degrees MARSDEN SQUARE: MMMUlaUlo Identifier and explain: MMM Marsden square Identifier and explain: UlaUlo Units digits in the reported latitude and longitude Top of Page SEA LEVEL PRESSURE: 99PoPoPo ToToToDoDo dodofofofo Identifier: 99 Indicator for data at the surface level follows Identifier: PoPoPo Indicator for pressure of specified levels in whole millibar (thousands digit omitted) Identifier: ToToTo Tens and digits of air temperature (not rounded off) in degrees Celsius, at specified levels beginning with surface Identifier: DoDo Dewpoint depression at standard isobaric surfaces beginning with surface level
NOTE
When the depression is 4.9C or less the units and tenths digits
of the depression are encoded. Depressions of 5.0 through 5.4C are
encoded as 50. Depressions of 5.5C through 5.9C are encoded as 56.
Dew point depressions of 6.0 and above are encoded in tens and units
with 50 added. Dew point depressions for relative humidities less then
20% are encoded as 80. When air temperature is below 40C report
DaDaas //
Identifier: dodo True direction from which the wind is
blowing rounded to nearest 5 degrees. Report hundreds and tens digits. The unit (0 and 5)
is added to the hundreds digit of wind.
Identifier: fofofo Wind speed in knots. Hundreds
digit is sum of hundreds digit of speed and unit digit of direction. Example: 295 degrees
at 125 knots is encoded as 29625
STANDARD ISOBARIC SURFACES: P1P1h1h1h1
T1T1T1D1D1 d1d1f1f1f1
Identifier: P1P1 Pressure of standard isobaric surfaces in
units of tens of millibars. (1000mbs = 00, 925mbs = 92, 850mbs = 85, 700mbs = 70, 500mbs =
50, 400mbs = 40, 300mbs = 30, 250mbs = 25)
Identifier: h1h1h1 Heights of the standard
pressure level in geopotential meters or decameters above the surface. Encoded in
decameters at and above 500mbs omitting, if necessary, the thousands or tens of thousands
digits. Add 500 to hhh for negative 1000mb or 925mb heights. Report 1000mb group as 00///
///// ///// when pressure is less than 950mbs.
Identifier: T1T1T1D1D1
Same temperature/dew point encoding procedures apply to all levels
Identifier: d1d1f1f1f1
Same wind encoding procedures apply to all levels
DATA FOR TROPOPAUSE LEVELS: 88PnPnPn TnTnTnDnDn
dndnfnfnfn
Identifier: 88 Indicator for Tropopause level follows
Identifier: PnPnPn Pressure at the tropopause
level reported in whole millibars. Report 88PnPnPn as
88999 when tropopause is not observed
Identifier: TnTnTnDnDn
Same temperature/dew point encoding procedures apply
Identifier: dndnfnfnfn - Same
wind encoding procedures apply
MAXIMUM WIND DATA: 77PnPnPn dndnfnfnfn
4vbvbvava
Identifier: 77 Indicator that data for maximum wind level and for vertical wind
shear follow when max wind does not coincide at flight. If the maximum wind level
coincides with flight level encode as 66
Identifier: PnPnPn Pressure at maximum wind
level in whole millibars
Identifier: dndnfnfnfn
Same wind encoding procedures apply
Identifier: 4 Data for vertical wind shear follow
Identifier: vbvb Absolute value of vector difference
between max wind and wind 3000 feet BELOW the level of max wind, reported to the nearest
knot. Use "//" if missing and a 4 is reported. A vector difference of 99 knots
or more is reported with the code figure "99".
Identifier: vava Absolute value of vector difference
between max wind and wind 3000 feet ABOVE the level of max wind, reported to the nearest
knot. Use "//" if missing and a 4 is reported. A vector difference of 99 knots
or more is reported with the code figure "99".
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AIRCRAFT AND MISSION IDENTIFICATION: 61616 AFXXX XXXXX XXXXX OB X KXXX
Identifier: 61616 Aircraft and mission identification data follows
Identifier: AFXXX The identifier AF for U.S. Air Force and the last three digits
of the aircrafts tail number
Identifier: XXXXX XXXXX The identifier for the type of mission being flown.
If a training mission the mission identifier is WXWXA TRAIN. The fifth letter
"A" is the only character that could possibly change. The "A" defining
that the flight is in the Atlantic basin. The letter "C" identifies the Central
Pacific area and the letter "E" identifies the Eastern Pacific.
If an operational storm mission: the first two numbers Identifies the number of times an
aircraft has flown this system and the second two numbers identifies the system number.
The last character again identifies the basin flown. The name of the storm would replace
TRAIN. EXAMPLE: AF968 0204A BONNIE Aircraft 50968, this was the second flight into
this system and the system was the fourth of the season. The system reached tropical storm
strength and was named BONNIE.
Identifier: OB 04 The observation (both vertical and horizontal) number as
transmitted from the aircraft.
NATIONALLY DEVELOPED CODES: 62626
Identifier: 62626 This is the remarks section. Only the remarks: EYE EYEWALL XXX
(eyewall will be followed by the radian to the eye center procured from the ARWO), or
RAINBAND, if release was made in a feeder band. The splash location will be recorded
automatically by computer. Followed by last wind height in meters and the mean boundary
layer wind with degrees to the nearest five-degree and knots.
PART BRAVO (B)
XXBB – Identifier for a temp drop code
Date/Time Group: YYGG8
Identifier: YY – Date Group
Identifier: GG – Time Group
Identifier: 8 - Indicator group for the use of satellite navigation for windfinding
LATTITUDE: 99LaLaLa
Identifier: 99 – Indicator for data on position follows
Identifier: LaLaLa – Latitude in tenths of degrees
LONGITUDE: QcLoLoLoLo
Identifier: Qc – The octant of the globe
Identifier: LoLoLoLo – Longitude in
tenths of degrees
MARSDEN SQUARE: MMMUlaUlo
Identifier and explain: MMM – Marsden square
Identifier and explain: UlaUlo – Units digits in the reported
latitude and longitude
SEA LEVEL PRESSURE: 00PoPoPo ToToToDoDo
Identifier: 00 – Indicator for data at the surface level follows
Identifier: PoPoPo – Indicator for pressure of
specified levels in whole millibars (thousands digit omitted)
Identifier: ToToTo – Tens and digits of air
temperature (not rounded off) in degrees Celsius, at specified levels beginning with
surface
Identifier: DoDo – Dewpoint depression at standard isobaric
surfaces beginning with surface level
NOTE SIGNIFICANT ISOBARIC LEVELS: nonoPoPoPo
ToToToDoDo
Identifier: nono – Number of level starting with surface
level. Only surface will be numbered as "00". When a standard level is also
selected as significant, repeat the level.
Identifier: PoPoPo – Pressure at specified levels
in whole millibars.
Identifier: ToToToDoDo –
Same temperature/dew point encoding applies.
SOUNDING SYSTEM INDICATION, RADIOSONDE/SYSTEM STATUS, LAUNCH TIME: 31313 srrarasasa 8GGgg
Identifier: srrarasasa –
Sounding system indicator, radiosonde/system status
Identifier: sr – Solar and infrared radiation correction ( 0 – no
correction)
Identifier: rara – Radiosonde/sounding system used
(96 – Descending radiosonde)
Identifier: sasa – Tracking technique/status of system used
(08 – Automatic satellite navigation)
Identifier: 8GGgg – Launch time
Identifier: 8 – Indicator group
Identifier: GG – Time in hours
Identifier: gg – Time in minutes
Top of Page 61616, 62626 – Same procedures as Part A
ADDITIONAL DATA GROUPS: 51515 101XX 0PnPnPnPn
Identifier: 51515 – Additional data in regional code follow
Identifier: 10166 – Geopotential data are doubtful between the following levels 0PnPnPnPn.
This code figure is used only when geopotential data are doubtful from one level to
another.
Identifier: 10167 – Temperature data are doubtful between the following levels 0PnPnPnPn.
This code figure shall be reported when only the temperature data are doubtful for a
portion of the descent. If a 10167 group is reported a 10166 will also be reported.
EXAMPLE: Temperature is doubtful from 540mbs to 510mbs. SLP is 1020mbs. The additional
data groups would be : 51515 10166 00251 10167 05451
Identifier: 10190 – Extrapolated altitude data follows:
When the sounding begins within 25mbs below a standard surface, the height of the
surface is reported in the format 10190 PnPnhnhnhn.
The temperature group is not reported. EXAMPLE: Assume the release was made from 310mbs
and the 300mb height was 966 decameters. The last reported standard level in Part A is the
400mb level. The data for the 300mb level is reported in Part A and B as 10190 30966
When the sounding does not reach surface, but terminates within 25mbs of a standard
surface, the height of the standard surface is reported in Part A of the code in standard
format and also at the end of Part A and Part B of the code in the format as 10190 PnPnhnhnhn.
EXAMPLE: Assume termination occurred as 980mbs and the extrapolated height of the 1000mb
level was 115 meters. The 1000mb level would be reported in Part A of the code as 00115
///// ///// and in Part B as 10190 0015.
Identifier: 10191 – Extrapolated surface pressure preceds. Extrapolated surface
pressure is only reported when the termination occurs between 850mbs and the surface.
Surface pressure is reported in Part A as 99PoPoPo /////
and in Part B as 00PoPoPo /////. When surface pressure is
extrapolated the 10191 group is the last additional data group reported in Part B.
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VORTEX REPORT CODE
MESSAGE HEADER. The first line of the message is the code used to
identify a vortex message in various meteorological data bases,
followed by the date and time (Zulu) the message was transmitted.
A. DATE AND TIME OF FIX. The time when the center of the storm was located
or "fixed". 05/1237Z means the report is from the fifth day of the month,
at 1237Z. "Z" means Zulu time, or Greenwich Mean Time (CDT + 5 hrs).
Therefore, 1237Z = 7:37 a.m. Central Daylight Savings Time.
<B. LATITUDE AND LONGITUDE of the vortex fix in degrees and minutes.
Example: 30 DEG 59 MIN N 77 DEG 16 MIN W.
Use this information to plot up the latest location of the storm center; comparing
the current position to previous positions gives the latest movement of the storm.
But be aware that sometimes storms "wobble", or make sharp turns, so listen to
the latest National Hurricane Center forecasts if you want to know where the
storm might be headed next!
C. MINIMUM HEIGHT AT STANDARD LEVEL. Standard level refers to certain
"slices" of the atmosphere used by meteorologists around the world. The exact altitude
of each of these slices relates to the pressure. The lower this height is below the
"standard" height indicates how low the pressure is inside the hurricane; stronger
storms have lower pressures. The number reported is in meters. Hurricane Hunters
fly storms at the "surface" (500 to 1500 feet above the water), 925 millibars (2500 feet or
762 meters), 850 mb (4780 ft or 1457 m), or 700 mb (9880 ft or 3011 m). The
aircraft will fly using an autopilot set to follow a constant pressure altitude.
For example, when flying a mission at 700 mb, the aircraft's pressure altimeter will
read 9,880 feet all day. But as the plane flies into lower pressure, the plane will
actually be flying closer to the ground. A radar altimeter bounces radar pulses off
the ground and tells the crew how high they actually are, and the meteorologist
uses this number to calculate the height of standard surface. In the example above,
the 700 millibar height was 2695 meters, which is 316 meters lower than the standard
height of 3011 meters: a significant low pressure! When flying low-level (below
1500 feet) this block is reported as NA (Not Applicable).
D. ESTIMATE OF MAXIMUM SURFACE WIND OBSERVED IN KNOTS. 65 kt means
the highest estimated surface wind is 65 knots on this particular inbound leg. The flight
meteorologist looks at the sea surface and can estimate how strong the winds are by what the
sea looks like. At particular wind speeds, the sea begins to form white caps, then patches of
foam, then some of the foam patches begin to appear green, etc. The key word here is
"observed"; the meteorologist may not see the highest surface winds because of darkness,
heavy rain or clouds, so often this number is lower than the maximum flight level wind.
A "knot" is a nautical mile (nm) per hour. To convert to miles per hour, use 1.15 miles/nm;
65 nm/hr x 1.15 mi/nm = 75 miles per hour. To convert to meters per second, cut knots in
half: 65 kt = 33 m/s. If not observed at all, this block is reported as NA (Not Applicable).
E. BEARING AND RANGE FROM CENTER OF THE MAXIMUM SURFACE WIND given in degrees
and nautical miles. The "bearing" is the direction from the center in which
the surface wind was seen, reported in degrees (similar to compass headings, except these
bearings are in reference to "true" instead of "magnetic" north). Due north is 0 degrees,
east is 90 degrees, south is 180 degrees, and west is 270 degrees. The bearing in the example is
050 degrees, which means the surface wind was seen northeast of the center. To pinpoint where
this was, you also need to know how far away it was: the "range". In this case, the 65 knot wind
reported in part D was found 80 nautical miles (92 statute miles) northeast of the center.
F. MAXIMUM FLIGHT LEVEL WIND NEAR STORM CENTER. The highest wind seen on
the last 100 mile leg inbound to the storm. There may be stronger winds in other sections of
the storm (see remarks in Item P). These winds are at flight level, and were measured
directly by the aircraft's instruments. In the example, the peak wind was 313 degrees 78 knots,
which means the wind was blowing from a direction of 313 deg (northwest) at a speed of 78 kts
(using the 1.15 mph/kt conversion, that's 90 miles per hour). Together with pressure (Items C and H),
winds give an idea of how strong the storm currently is.
G. BEARING AND RANGE FROM CENTER OF MAXIMUM FLIGHT LEVEL WIND. Same
method as reporting bearing and range for the surface winds (see Item E, above). In this example,
the 78 knot flight level wind reported in Item F was found 063 degrees (northeast) of the center,
and 32 nautical miles from the center. Usually the strongest winds are found in the "eyewall"
surrounding the eye, and this gives an idea of how large the center (or eye) of the storm is.
H. MINIMUM SEA LEVEL PRESSURE computed from dropsonde or extrapolation. This is one
of the key pieces of information which tell how strong the storm is. "Standard" sea level pressure
is 1013 millibars. Since hurricanes, tropical storms, and tropical depressions are all low-pressure
systems, the pressure reported here is almost always lower than standard. The lower the pressure,
the more intense the storm. The word "EXTRAP" precedes any pressures extrapolated from aircraft
sensor information; if the word "EXTRAP" is not there, it means the pressure was measured directly
by a dropsonde released from the aircraft, and is usually more accurate. This lowest pressure is found
in the center of the storm. Millibars can be converted to inches of Mercury using 0.0295 in-Hg/mb.
In the example, the pressure of 954 mb is approximately 28.14 in-Hg. For reference, developing
storms may have pressures around 1007 mb, most hurricanes are below 980 mb, and the lowest
pressure measured in an Atlantic/Gulf of Mexico hurricane was 888 mb (Hurricane Gilbert). There
may be small fluctuations in pressure due to normal, daily pressure rises and falls.
I. MAXIMUM FLIGHT LEVEL TEMPERATURE / PRESSURE ALTITUDE
OUTSIDE THE EYE. This gives an idea of the general temperature surrounding
the storm. "Standard" temperature at 700 mb (where we fly most hurricanes) is
about -5 degrees Celsius, but in the tropics, it's usually 10 to 15 degrees warmer than
"standard". What you especially want to look for is how it compares to the temperature
inside the eye, in Item J or P. The example shows a temperature of 11 degrees Celsius
(52 degrees Fahrenheit) at an altitude of 3082 meters (10,112 feet). The altitude is
included because the airplane bumps up and down due to turbulence and other factors,
and minor changes in the temperature may be due to changes in altitude.
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J. MAXIMUM FLIGHT LEVEL TEMPERATURE / PRESSURE ALTITUDE
INSIDE THE EYE. This is yet another indicator of how "healthy" the storm is.
One of the unusual features of a hurricane is that it is warmer inside the eye than
outside. What you want to look for here is how much warmer it is than the
temperature reported outside the eye in Item "I." A developing storm may be only
a degree warmer inside the center, while a strong hurricane may be 10 degrees
warmer. In this example, the eye temperature of 15 degrees Celsius (59 degrees
Fahrenheit) is four degrees warmer than the temperatures immediately outside
the eye. Be sure to look at the remarks in Item "P" to see if there was an even
warmer temperature found inside the eye (but more than 5 miles from the fix position).
The aircraft was at a pressure altitude of 3108 meters (10,198 feet).
K. DEWPOINT TEMPERATURE / SEA SURFACE TEMPERATURE
INSIDE THE EYE. This is the "dewpoint" measured in the center of the storm.
Dewpoint is a measure of the humidity. If the dewpoint and the temperature are
exactly the same, the humidity is 100%. The formula for converting to relative
humidity is too complicated to explain here, but the lower the dewpoint is,
compared to the air temperature, the drier the air. In the example, the dewpoint
was 13 Celsius (compared to a temperature of 15 Celsius), for a relative humidity
of 87%. If the humidity is at or near 100%, it may mean the center is filled with
clouds near the altitude of the aircraft, while a "healthy" hurricane may have a
clear, drier eye. The second part of Item K is no longer used, as the aircraft
do not carry the infrared sensors needed to measure sea surface temperature.
L. EYE CHARACTER. This is a brief description of what the eye looks like on
radar. "CLOSED WALL" if the eye is completely surrounded by a ring of
thunderstorms: the wall cloud. "OPEN NE" means there is a break in the wall
to the northeast, etc. If the eye is not at least 50% surrounded by a wall cloud,
this item and Item M will be reported as "NA" (Not Applicable).
M. EYE SHAPE ORIENTATION AND DIAMETER. Eye shapes are coded as
follows: C-circular; CO-concentric; E-elliptical. Orientation of major axis of
ellipse is transmitted in tens of degrees, and all diameters are transmitted in
nautical miles. Example: E09/15/5 means elliptical eye oriented with major
axis thru 90 degrees (and also 270 degrees), with length of major axis 15 nm,
and length of minor axis 5 nm. CO8-14 means concentric eye with inner eye
diameter 8 miles, and outer diameter 14 miles.
The "healthiest" hurricanes usually have a small, circular eye. A concentric
eye (a ring inside a ring) is a relatively rare phenomenon that may signal
a temporary weakening while the storm reorganizes. An eye diameter that
shrinks (compared to the previous vortex message) may signal strengthening: just
as a twirling ice skater spins faster as she pulls in her arms, a hurricane may "spin"
faster as its eye gets smaller. Eye diameters are usually 10-20 nautical miles, while
we sometimes see them as small as 5 nm to as large as 60 nm.
N. FIX DETERMINED BY / FIX LEVEL. The first string of numbers indicates
what the meteorologist used to find the center of the storm, using numbers 1
through 5, as follows:
1-Penetration, 2-Radar, 3-Wind, 4-Pressure, 5-Temperature.
After the solidus ("/"), you'll find one or two numbers which show at what level(s)
the center was found, as follows:
0-surface, 1-1500 ft, 8-850 mb, 7-700 mb, 5-500 mb, 4-400 mb, 3-300 mb, 2-200 mb, 9-925 mb.
Example: 1235/7 means the fix was determined by four means: penetration, radar,
winds, and pressure. The fix was made at 700 mb (approx 10,000 feet). If a calm
spot was seen on the surface of the water, the fix level could have been "07" to
indicated the surface and the 700 mb center were found within 5 nm of each other.
O. NAVIGATION FIX ACCURACY / METEOROLOGICAL ACCURACY.
These numbers give an estimate of how accurate the position is. "Navigation
accuracy" is a gauge of how well the navigation equipment is operating. The
"Meteorological Accuracy" depends on how well the storm center can be
defined by the meteorological data: if there is a sudden, sharp wind shift, and
the temperature peak and pressure drop all coincide, the met accuracy will be
a small number. A weaker storm will probably have a larger met accuracy.
Both numbers are reported in nautical miles.
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P. REMARKS SECTION.
Always starts with the Mission ID:
MISSION IDENTIFIER. The first line of the remarks is a unique identifier
for each mission:
AFXXX AABBC NAME
Agency: Either AF for the Air Force Reserve Hurricane Hunters or
NOAA for the National Oceanic and Atmospheric Agency aircraft
XXX: Tail number of the aircraft
AA: Total number of missions flown on this storm system
BB: Depression number (or "XX" if it's not a depression or greater)
C: Ocean basin. "A"=Atlantic, "C"=Central Pacific, "E"=Eastern Pacific
NAME: Storm name, or words CYCLONE (for depression) or INVEST.
Example: AF984 1606A FRAN means Air Force Reserve aircraft number 984
is flying the 16th mission on Hurricane Fran, which is the 6th tropical cyclone
of the season in the Atlantic/Gulf/Carribbean.
The flight meteorologist may add details of
anything he or she feels are interesting to note. There are some standard
remarks: "MAX FL WIND 105 KT NE QUAD 1051Z" reminds the public that
while the highest wind seen just prior to hitting the center this time around
was 78 knots (Item F), a stronger wind was seen earlier in the flight: 105 knots
at 1051Z (5:51 a.m. CDT), in the northeast quadrant of the storm. Another
standard remark is given anytime a temperature peak is seen more than 5 nm
from the center location: "MAX FL TEMP 17C 130/10 NM FROM FL CENTER"
says the highest temperature seen at flight level ("FL") was 17 Celsius, located
10 nautical miles in a direction of 130 degrees (to the southeast). Finally, the
meteorologist lets you know Fran has a "STADIUM EFFECT", a rare but lovely
phenomenon in which the clouds form a solid wall all around the eye, and stretch
up and outward to reveal a circle of clear sky above, similar to a football stadium
that's 50,000 feet tall! Take the
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VORTEX DATA CODE
URPA14 is the name of this report. Pacific reports are coded URPA14
PGTW is the location of the recipient of the message (Joint Typhoon Warning Center)
DDTTTT is the day and time of the report in Greenwich Mean Time
AA is the Agency providing the report. AF is Air Force, NOAA is NOAA
### is the aircraft number flying the mission
MM is the number of the mission for this storm
XX is the depression number, or simply XX if not a depression or greater
NAME is the name of the storm, if any, or words CYCLONE or INVEST
LaLaLa is the latitude of the report in degrees/tenths
LoLoLoLo is the longitude of the report in degrees/tenths
jHHH is the pressure height data in the following format:
j=0 means sea level data follows with HHH in whole millibars
j=2 means 850 mb data follows with HHH in geopotential meters
j=3 means 700 mb data follows with HHH in geopotential meters
j=8 D - Value in geopotential decameters; if neg, 500 is added to HHH
j=9 means 925 mb data follows with HHH in geopotential meters
TTTdTd is the temperature/dewpoint in degrees Celcius. If the temperature or
dewpoint is greater than 50, it means it is negative. Subtract 50 from the number
and add a negative sign to decode. Example: TdTd=58 decodes to -8 Celsius.
ddfff is the true direction of flight level wind in tens of degrees, and fff is
the speed of wind in knots (multiply by 1.15 to convert to miles per hour).
/ means data unknown or unobtainable
MF means that maximum flight level wind data follows, in the following format:
MFLaLaLa MLoLoLoLo MF fff. The first two blocks are the latitude and
longitude of the max wind, in degrees and tenths. The last block is the windspeed
in knots.
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Automatic Met Report from an Aircraft
YYGG--Day and Hour of the report.
ipipip--Phase of the Flight Indicator. This indicator
shows both the phase of the flight (unsteady, level, ascent or descent) and, in the case of level flight,
the type of observation (routine or maximum wind).
IA...IA--Aircraft Identifier.
LaLaLaLaA--Latitude.
LaLaLaLaA--Latitude in degrees and minutes.
A--Direction of latitude (N or S).
LoLoLoLoLoB--Longitude.
LoLoLoLoLo--Longitude in degrees and minutes.
B--Direction of longitude (E or W).
GGgg--Time of observation in hours and minutes.
ShhIhIhI--Pressure altitude in hundreds of feet.
SSTATATA--Air temperature.
SS--Sign of the temperature (PS = Plus or positive, MS = Minus or negative temperatures).
TATATA--Air temperature, in tenths of a degree Celsius, at the level given
by hIhIhI.
{SSTdTdTd or UUU}--Dew Point Temperature or Relative Humidity
(either one or the other is given).
SSTdTdTd--Dew Point Temperature.
SS--Sign of the Dew Point Temperature (same as temperature).
TdTdTd--Dew Point temperature, in tenths of degrees Celsius.
UUU--Relative Humidity of the air in percent (first digit is always 0 unless 100% humidity).
ddd/fff--Winds.
ddd--True direction in whole degrees, from which the wind is blowing.
fff--Wind speed, in knots, at the level indicated by hIhIhI.
TBBA--Turbulence.
SS1S2S3--System information.
S1--Type of navigation system.
S2--Type of system used.
S3--Temperature precision.
333--Indicator for data on pressure altitude and maximum derived equivalent vertical
gust follow.
Fhdhdhd--Pressure Altitude as reported by ACARS systems.
VGfgfgfg--Maximum derived equivalent vertical gust,
in meters per second.
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