KEY TO DECODE AN ASOS (METAR) OBSERVATIONMETAR KABC 121755Z AUTO 21016G24KT 180V240 1SM R11/P6000FT -RA BR BKN015 OVC025 06/04 A2990
RMK AO2 PK WND 20032/25 WSHFT 1715 VIS 3/4V1 1/2 VIS 3/4 RWY11 RAB07 CIG 013V017 CIG 017 RWY11 PRESFRSLP125 P0003 60009 T00640036 10066 21012 58033 TSNO $TYPE OF REPORTMETAR: hourly (scheduled) report; SPECI: special (unscheduled) report.

METAR

STATION IDENTIFIER

Four alphabetic characters; ICAO location identifier.

KABC

DATE/TIME

All dates and times in UTC using a 24-hour clock; two-digit date and four-digit time;always appended with Z to indicate UTC.

121755ZAUTOREPORT MODIFIER

Fully automated report, no human intervention; removed when observer signed-on.

WIND DIRECTION AND SPEED

Direction in tens of degrees from true north (first three digits); next two digits: speed inwhole knots; as needed Gusts (character) followed by maximum observed speed; always
appended with KT to indicate knots; 00000KT for calm; if direction varies by 60° or more 21016G24KT
180V240
a Variable wind direction group is reported.

VISIBILITY

Prevailing visibility in statute miles and fractions (space between whole miles andfractions); always appended with SM to indicate statute miles; values <1/4 reported as
M1/4.

1SM

RUNWAY VISUAL RANGE

10-minute RVR value in hundreds of feet; reported if prevailing visibility is ≤ one mile orRVR ≤ 6000 feet; always appended with FT to indicate feet; value prefixed with M or P toR11/P6000FT
indicate value is lower or higher than the reportable RVR value .

WEATHER PHENOMENA

RA: liquid precipitation that does not freeze; SN: frozen precipitation other than hail; UP:precipitation of unknown type; intensity prefixed to precipitation: light (-), moderate (nosign), heavy (+); FG: fog; FZFG: freezing fog (temperature below 0°C); BR: mist; HZ:haze; SQ: squall; maximum of three groups reported; augmented by observer: FC (funnelcloud/tornado/waterspout); TS (thunderstorm); GR (hail); GS (small hail; <1/4 inch);
FZRA (intensity; freezing rain); VA (volcanic ash).

-RA BR

Cloud amount and height: CLR (no clouds detected below 12000 feet); FEW (few); SCT(scattered); BKN (broken); OVC (overcast); followed by 3-digit height in hundreds offeet; or vertical visibility (VV) followed by height for indefinite ceiling.

BKN015 OVC025

Each is reported in whole degrees Celsius using two digits; values are separated by asolidus; sub-zero values are prefixed with an M (minus).

06/04

Altimeter always prefixed with an A indicating inches of mercury; reported using four
digits: tens, units, tenths, and hundredths.

A2990

SKY CONDITIONTEMPERATURE/DEW POINT
ALTIMETER

REMARKS ON REVERSE SIDEREMARKS IDENTIFIER: RMKTORNADIC ACTIVITY: Augmented; report should include TORNADO, FUNNEL CLOUD, or WATERSPOUT, time begin/end, location, movement;e.g., TORNADO B25 N MOV E.

RMKTYPE OF AUTOMATED STATION: AO2; automated station with precipitation discriminator.
PEAK WIND: PK WND dddff(f)/(hh)mm; direction in tens of degrees, speed in whole knots, and time.
WIND SHIFT: WSHFT (hh)mm

AO2PK WND 20032/25
WSHFT 1715

TOWER OR SURFACE VISIBILITY: TWR VIS vvvvv: visibility reported by tower personnel, e.g., TWR VIS 2; SFC VIS vvvvv: visibility reportedby ASOS, e.g., SFC VIS 2.
VARIABLE PREVAILING VISIBILITY: VIS vnvnvnvnvnVvxvxvxvxvx; reported if prevailing visibility is < 3 miles and variable.
VISIBILITY AT SECOND LOCATION: VIS vvvvv [LOC]; reported if different than the reported prevailing visibility in body of report.

VIS 3/4V1 1/2
VIS 3/4 RWY11

LIGHTNING: [FREQ] LTG [LOC]; when detected the frequency and location is reported, e.g., FRQ LTG NE.
BEGINNING AND ENDING OF PRECIPITATION AND THUNDERSTORMS: w'w'B(hh)mmE(hh)mm; TSB(hh)mmE(hh)mm
VIRGA: Augmented; precipitation not reaching the ground, e.g., VIRGA.
VARIABLE CEILING HEIGHT: CIG hnhnhnVhxhxhx; reported if ceiling in body of report is < 3000 feet and variable.
CEILING HEIGHT AT SECOND LOCATION: CIG hhh [LOC]; Ceiling height reported if secondary ceilometer site is different than the ceiling heightin the body of the report.
PRESSURE RISING OR FALLING RAPIDLY: PRESRR or PRESFR; pressure rising or falling rapidly at time of observation.
SEA-LEVEL PRESSURE: SLPppp; tens, units, and tenths of SLP in hPa.
HOURLY PRECIPITATION AMOUNT: Prrrr; in .01 inches since last METAR; a trace is P0000.
3- AND 6-HOUR PRECIPITATION AMOUNT: 6RRRR; precipitation amount in .01 inches for past 6 hours reported in 00, 06, 12, and 18 UTC
observations and for past 3 hours in 03, 09, 15, and 21 UTC observations; a trace is 60000.
24-HOUR PRECIPITATION AMOUNT: 7R24R24R24R24; precipitation amount in .01 inches for past 24 hours reported in 12 UTC observation,e.g., 70015.

RAB07
CIG 013V017
CIG 017 RWY11PRESFRSLP125P0003
60009

HOURLY TEMPERATURE AND DEW POINT: TsnTaTaTasnT'aT'aT'a; tenth of degree Celsius; sn: 1 if temperature below 0°C and 0 if temperature 0°C
T00640036
or higher.
6-HOUR MAXIMUM TEMPERATURE: 1snTxTxTx; tenth of degree Celsius; 00, 06, 12, 18 UTC; sn: 1 if temperature below 0°C and 0 if temperature0°C or higher.
6-HOUR MINIMUM TEMPERATURE: 2snTnTnTn; tenth of degree Celsius; 00, 06, 12, 18 UTC; sn: 1 if temperature below 0°C and 0 if temperature
0°C or higher.
24-HOUR MAXIMUM AND MINIMUM TEMPERATURE: 4snTxTxTxsnTnTnTn; tenth of degree Celsius; reported at midnight local standard
time; 1 if temperature below 0°C and 0 if temperature 0°C or higher, e.g., 400461006.
PRESSURE TENDENCY: 5appp; the character (a) and change in pressure (ppp; tenths of hPa) the past 3 hours.
SENSOR STATUS INDICATORS: RVRNO: RVR missing; PWINO: precipitation identifier information not available; PNO: precipitation amount notavailable; FZRANO: freezing rain information not available; TSNO: thunderstorm information not available; VISNO [LOC]: visibility at secondary
location not available, e.g., VISNO RWY06; CHINO [LOC]: (cloud-height-indicator) sky condition at secondary location not available, e.g., CHINO
RWY06.
MAINTENANCE CHECK INDICATOR: Maintenance needed on the system.

10066
21012

58033

TSNO
$If an element or phenomena does not occur, is missing, or cannot be observed, the corresponding group and space are omitted (body and/or remarks) from that particular report, except for Sea-Level Pressure (SLPppp). SLPNO shall be reported in a METAR when the SLP is not available.
U.S. DEPARTMENT OF COMMERCE - NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION - National Weather Service - Observing Systems Branch, 1325 East-West Highway, Silver Spring, Maryland 20910

METAR\TA2\2-8-96