METAR Format (FM-15)

Surface Meterological Airways Format


Syntax:

METAR CCCC TIME AUTO WIND VISIBILITY WEATHER CLOUDS TEMP/DEW ALTIMETER REMARKS

METAR

This defines the product type.  This can either be the string "METAR" for a regularly reported observation (such as an hourly) or "SPECI" for a special observation.

CCCC

CCCC is the 4 letter ID uniquely defining the reporting station, for example KORD for O'Hare airport in Chicago.

TIME

The full universal time (UTC) that the observation was taken.  The format is:

ddhhmmZ.  

dd is the day of the month, hh is the hour, mm is the minute.

AUTO

This is an optional grouping used to specify a station as being automated.

WIND

The wind group

dddssKT or dddssGggKT

The value ddd is the wind direction in degrees.  The value ss is the wind speed.  The units are defined by the string "KT" which is knots. Some reports may have "MPS" for meters per second. If wind gusts are reported, they are specified with the group "Ggg".

VISIBILITY

The visibility group

vvSM or vvKM

This specifies the visibility is either statue miles "SM" or kilometers "KM".  The visibility can be partial values such as "1 1/2SM" or "3/16SM".

WEATHER

The weather group

iiddppooxx

ii is intensity group
ii Description
- light
moderate
+ heavy
VC in the vicinity

dd is the descriptor group
dd Description
MI shallow
PR partial
BC patches
DR low drifting
BL blowing
SH shower
TS thunderstorm
FZ freezing

pp is the precipitation group
pp Description
DZ drizzle
RA rain
SN snow
SG snow grains
IC ice crystals
PE ice pellets
GR hail
GS small hail/snow pellets
UP unknown

oo is the obscuration group
oo Description
BR mist
FG fog
FU smoke
VA volcanic ash
DU dust
SA sand
HZ haze
PY spray

xx is the misc group
xx Description
PO dust whirls
SQ squalls
FC funnel cloud/tornado/waterspout
SS duststorm

CLOUDS

The cloud levels

ccchhhtt

ccc is the coverage
CLR or SKC = clear
FEW = 1/8 coverage
SCT = 2,3,4/8 coverage
BKN = 5,6,7/8 coverage
OVC = overcast
VV = vertical visibility for obscuration

hhh is the height of base in 30m or 100ft increments. ie 30 = 3000 feet

tt is an optional type
CU = cumulus
CB = cumulonumbus
TCU = towering cumulus
CI = cirrus

CAVOK = clear skies, unlimited visibility

TEMP/DEW

is the temperature and dewpoint in Celsius

TT/DD

negative values are preceded with a M (M03 = -3)

ALTIMETER

is the altimeter setting

Qpppp = altimeter in whole mb

Apppp = altimeter in .01 in Hg

REMARKS

The remark section:

RMK xxxx xxxx xxxx...
Remark Description
AO1 AMOS station
AO2 ASOS station
OBS TAKEN +xx minute offset for observation time
SLPppp Sea level pressure in .1 mb (142 = 1014.2 mb)
WEA:www Additional present weather information
Tttttdddd Current temperature/dewpoint in .1C
T01720144 = temp=17.2C, dew=14.4C, first digit 1 for negative
1xxxx 6 hour max temp in .1C, first digit 1 for negative
2nnnn 6 hour min temp in .1C, first digit 1 for negative
4/sss Snow coverage in inches
4xxxxnnnn 24 hour max/min temps in .1C, first digit 1 for negative
5tppp Pressure tendency in .1 mb for 3 hours, t is the trend
6pppp 6 hour precipitation in .01 inches
7pppp 24 hour precipitation in .01 inches
8/lmh Cloud type for low, medium, high
933sss New snow coverage, water equivalent
98mmm Equivalent sunshine for day in minutes
CITY tt City temperature
PCPN pppp
Ppppp
1 hour precipitation
PK WND sss/nn Peak wind, sss is speed, nn is the time
PRESFR Pressure falling rapidly
PRESRR Pressure rising rapidly
SNOINCR xxx Snow increasing rapidly, where xxx is amount of snow in last hour
WSHFT nn Wind shift at time nn

Examples

CCCC TIME WIND VIS WEA CLOUD TT/DD ALT REMARKS
KLAF 030445Z 35007KT 15SM SKC 17/13 A2986

KLAF = Station Identifier
030445Z = Time (ddhhmmZ)
35007KT = Winds (350 deg at 7 knots)
15SM = Visibility (15 statute miles)
SKC = Clear skies
17/13 = Temperature/Dewpoint in Celsius
A2986 = Altimieter setting (29.86 in Hg)

CCCC TIME WIND VIS WEA CLOUD TT/DD ALT REMARKS
KLAF 021915Z COR 22010KT 7SM TSRA BKN055 30/17 A2974 RMK T W MOVG NE

TSRA = Weather (TS-Thunderstorm RA-Rain)
BKN055 = Cloud level (Broken at 5500 feet)

CCCC TIME WIND VIS WEA CLOUD TT/DD ALT REMARKS
KLAF 021950Z 30008KT 7SM -RA BKN065CB 25/21 A297 RMK TE40

BKN065CB = Cloud level (Broken at 6500 feet with cumulonimbus)

CCCC TIME WIND VIS WEA CLOUD TT/DD ALT REMARKS
LTCC 022250Z 32003KT CAVOK 24/10 Q1011 NOSIG=

CAVOK = Cloud/Visibility (OK=Clear with unlimited visibility)
Q1011 = Altimeter setting (1011 mb)

CCCC TIME WIND VIS WEA CLOUD TT/DD ALT REMARKS
KFHU 022336Z 33011G25 35SM TS VCSH FEW040 SCT060CB BKN100 BKN250 31/14 A3003 RMK WSHFT 27 FRQ LTGICCG TS N MOV W SHRA N AND NE-SE=

33011G25 = Winds (330 at 11 Gusts to 25)
TS VCSH = Weather (TS=Thunderstorm, VC=Vicinty, SH=Shower)
FEW040 = Clouds (FEW=few clouds or 1/8 coverage at 4000 feet)

CCCC TIME WIND VIS WEA CLOUD TT/DD ALT REMARKS
KIND 022356Z 26009KT 10SM CLR 24/20 A2973 RMK AO2 SLP062 60000 T02440200 10317 20228 56009 $=

AO2 = ASOS station
SLP062 = Sea level pressure (062=1006.2 mb)
60000 = 6 hour precipitation (0000=trace)
T02440200 = Current temperature/dewpoint (temp=0244=24.4C,dew=0200=20.0C)
10317 = 6 hour max temp (317=31.7C)
20228 = 6 hour min temp (228=22.8C)
56009 = Pressure tendency (6009=falling .9 mb in last 3 hours)