Weather Forecasting ... On-Line


This web page contains the standards for coding a weather obervation in either aviation routine weather report (METAR) and/or aviation special weather report (SPECI) format. The table below shows the generic format elements of a METAR/SPECI, the element content, and details on that element.

Generic METAR/SPECI Format

Message elements are shown in the order in which they are placed in the coded METAR.

Generic Format Element Content Element Details
METAR or SPECI type of report none
CCCC station identification four letter code to identify the station to which the report applies; location identifiers for the contiguous U.S. start with K
YYGGggZ date and time of report the actual time of the report or when the criteia for SPECI is met; YY is the day of the month; GGgg is the time in Zulu time (or UTC)
AUTO or COR report modifier AUTO indicates the observation if fully automated with no human intervention or oversight; COR indicates a corrected observation
wind speed and direction ddd = wind direction in tens of degrees
ff = wind speed in knots (two or three digits)
G = gust indicator followed by gust value
Variable wind direction
a. speeds 6 kts or less - VRB03KT
b. speed greater than 6 kt - dddVddd
c. calm wind - 000000KT
VVVVVSM surface visibility in statute miles; code values depend upon whether an automated or manual observation
runway visual range R = indicator followed by the runway number; reportable values of visual range or variable range values
w'w' present weather intensity or proximity; descriptor; precipitation; obscuration, or other phenomena
NsNsNshshshs or
VVhshshs or
sky condition NNNhhh = cloud amount and height (hundreds of feet)
a. SKC or CLR = 0/8 clooud cover
b. FEW = 1/8-2/8 cloud cover
c. SCT = 3/8-4/8 cloud cover
d. BKN = 5/8-7/8 cloud cover
e. OVC = 8/8 cloud cover
VVhhh = vertical visibility and height (hundreds of feet)
T'T'/T'dT'd temperature and dew point to the nearest whole degree Celcius; negative values start with M, e.g., M03 is -3 C
APHPHPHPH altimeter setting tens, units, tenths, hundredths of inches of mercury; no decimal point is coded
RMK remarks a. automated, manual, and plain language
b. additive and maintenance data

Please note that each element of a coded METAR observation is separated by a space. When an element does not occur, or cannot be observed, the corresponding group and preceding space are omitted from that particular report.


Automated, Manual, Plain Language

Generic Format Remark Content Remark Details
plain language volcanic eruption name of volcano, latitude/longitude, date/time of eruption; ash cloud description
tornadic activity B/E(hh)mm LOC/DIR (MOV) tornadoes
funnel clouds
type of phenomena; start or end time; location; movement
AO1 or AO2 type of automated station automated station
AO1 = without precip discriminator
AO2 = with precip discriminator
PK WND dddff(f)/(hh)mm peak wind peak wind speed/direction since the last METAR and time
example: PK WND 28045/15
WSHFT (hh)mm wind shift time the wind shift began; FROPA may be used after the time
example: WSHFT 30 FROPA
TWR VIS vvvvv or
SFC VIS vvvvv
tower or surface visibility when multiple observing sites exist
VIS vvvvvVvvvvv variable prevailing visibility if prevailing visibility is less than 3 miles and rapidly increases or decreases by 1/2 mile
example: VIS 1/2V2
VIS DIR vvvvv sector visibility VIS - remark identifier
DIR - sector to 8 points of compass
vvvvv - sector visibility
example: VIS NE 2 1/2
VIS vvvvv LOC visibility at a second location VIS - remark identifier
vvvvv - visibility at second location
LOC location
example: VIS 2 1/2 RWY11
Frequency LTG(type) LOC lightning frequency frequency:
a. OCNL - occasional
b. FRQ - frequent
c. CONS - continuous
a. CG - cloud to ground
b. IC - in cloud
c. CC - cloud to cloud
d. CA - cloud to air
w'w'B(hh)mmE(hh)mm beginning/end of precip w'w' - precip type
B - beginning indicator
E - end indicator
(hh)mmm - (hour) and minute
example: RAB05E30SNB20E55
TSB(hh)mmE(hh)mm beginning/end of thunderstorm example: TSB0159E30
TS LOC (MOV DIR) thunderstorm location LOC - location of thunderstorm
MOV DIR - movement with direction
example: TS SE MOV NE
GR size hailstone size GR - remark identifier
example: GR 1 3/4
VIRGA (DIR) virga VIRGA - remark identifer
DIR - direction from station
example: VIRGA SW
CIG hhhVhhh variable ceiling height CIG - remark identifier
hhh - ceiling height
example: CIG 005V010
w'w' NNNhhh obscurations w'w' - obscuration
NNN - sky cover amount of obscuration
hhh - height of obscuration
examples: FG SCT000, FU BKN020
NNN(hhh) V NNN variable sky condition NNN - sky cover amount
hhh - cloudceiling height
example: BKN014 V OVC
plain language significant cloud types possible cloud types:
a. CB - cumulonimbus
b. TCU - towering cumulus
c. ACC - altocumulus castellanus
CIG hhh LOC ceiling height at second location CIG - remark identifier
hhh - ceiling height
LOC - location of second ceilometer
example: CIG 002 RWY11
pressure rising or falling rapidly pressure rising/falling at a rate of 0.06 inch/hour
SLPppp sea level pressure SLP - remark identifier
ppp - sea level pressure in hectopascals
example: SLP982 (998.2 hPa)
ACFT MSHP aircraft mishap when an observation is taken when notified of an aircraft mishap
NOSPECI no SPECI reports taken at stations where no specials are taken
SNINCR inches-this hour/inches-on ground snow increaing rapidly whenever snow increases by 1 inch or more in the past hour
example: SNINCR 2/10
plain language other significant information example: FIRST or LAST

Additive and Maintenance Data

Generic Format Remark Content Remark Details
Prrrr hourly precip amount P - group indicator
rrrr - water equivalent of precip since last METAR in hundredths of an inch
example: P0000 - trace of precip
6RRRR 3-/6-hour precip amount 6 - group indicator
RRRR - amount of precip in last 3 or 6 hours in hundredths of an inch
6 hourly at 00Z, 06Z, 12Z, 18Z
3 hourly at 03Z, 09Z, 15Z, 21Z
example: 60217 = 2.17 inches
7RRRR 24-hour precip amount 7 - group indicator
RRRR - amount of precip in last 24 hours
example: 70125 = 1.25 inches
4/sss snow depth on ground 4/ - group indicator
sss - snow depth in whole inches
exaample: 4/021 = 21 inches
933RRR water equivalent of snow on ground 933 - group indicator
RRR - water equivalent of snow in tens, units, and tenths of inches
example: 933125 = 12.5 inches
8/CLCMCH cloud types predominatn type of low cloud (CL), middle cloud (CM), and high cloud (CH)
8/6// = low overcast stratus cloud (no middle or high cloud)
8/903 = low CB, no middle cloud, dense high cirrus
98mmm duration of sunshine 98 - group indicator
mmm - total minutes of sunshine
example: 98096 = 96 minutes of sunshine
TsTTTsDDD hourly temperature and dew point T - group indicator
s - sign of value (0-above zero; 1-below zero)
TTT - temperature in tens, units, tenths
DDD - dew point in tens, units, enths
example: T00261015 = T of 2.6 C and DP of -1.5 C
1sTTT 6-hourly max temperature 1 - group indicator
s - sign of value (0-above zero; 1-below zero)
TTT - max temperature in tens, units, tenths
2sTTT 6-hourly min temperature 2 - group indicator
s - sign of value (0-above zero; 1-below zero)
TTT - min temperature in tens, units, tenths
4sTTTsTTT 24-hour max/min temperature 4 - group indicator
s - sign of value (0-above zero; 1-below zero)
first TTT - max temperature in tens, units, tenths
second TTT - min temperature in tens, units, tenths
5appp 3-hourly pressure tendency 5 - group indicator
a - character of pressure change over the past 3 hours
ppp - amount of pressure change in tenths of hectopascals

METAR Example

METAR KOKC 041452Z 17011KT 10SM TS SCT065CB SCT110 OVC220 27/21 A2990 RMK A02 TSB46 SLP109 OCNL LTGICCG TS VC NE MOV SE SHRA N-NE T02670206 53006

METAR observation from Oklahoma City (KOKC) on the 4th day of the month at 1452Z (15Z). Wind is from the SSW (170 deg) at 11 knots. Visibility is 10 statute miles with thunderstorms (TS) over the airport. There are three cloud layers: scattered clouds at 6,500 feet (SCT065); scattered clouds at 11,000 feet (SCT110); and overcast clouds at 22,000 feet (OVC220). The temperature in whole degrees is 27 C and the dew point is 21 C. The altimeter setting is 29.90 inhces of mercury. The thunderstorm began at 46 minutes past the hour. Sea level pressure is 1010.9 hectopascals (millibars). There is occasional in-cloud and cloud-to-ground lightning. There are thunderstorms in the vicinity, northeast of the airport moving southeast. There are rain showers from north through northeast. The whole number temperature of 27 C is really 26.7 C while the whole number dew point of 21 is really 20.6 C. The character of the pressure change is a check rise (3) with an increase of 0.6 hectopascals.

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Last updated on 3/09/10