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What is a METAR?
• Acronym for METeorological Aviation Report• Generated at least once an hour (usually right
prior to the end) or when a significant change in weather occurs
• Composed of two parts: Body and Remarks• Information contained within is added in a
specific order and format
ExampleKHSV 121553Z 22010KT 3SM -RA BR OVC010 09/08 A2969 RMK AO2 RAB01E11B45 CIG 007V012 SLP053 P0000 T00940078
• Information ALWAYS given includes:• Station ID• Date/Time• Wind Speed/Direction• Visibility• Current Observed Weather• Sky conditions• Temperature/Dewpoint• Altimeter Reading (Pressure)
• Any information given after RMK are referred to as remarks, and this information can vary
Web Resources
Station ID Look-up:http://www.nws.noaa.gov/tg/siteloc.shtml
Federal Meteorological Handbook Chapter on METAR:http://www.ofcm.gov/fmh-1/pdf/L-CH12.pdf
Station ID
• Example = KABC• 4 character identifier for reporting stations• The first letter identifies the country. All US
stations begin with ‘K’, Canadian stations begin with ‘C’
• Next 3 characters identify the station.– KJAN is Jackson, MS for example
Date/Time
• Example = 121553Z• Given in Greenwich Mean Time, or Zulu• First two numbers are the day of the month.
Single dates are reported with a 0• Next 4 numbers are the time.
Report Modifier
• Example = AUTO• 3 possibilities: None, AUTO and COR• AUTO means the observation was taken
without human interaction or oversight• COR indicates a correction to a previous report• If nothing, then a human took the observation
Wind Direction and Speed
• Example = 21016G24KT 180V240• First three numbers denote the direction given
in degrees.• The next two numbers are speed in knots• In this example, the G indicates that a gust
occurred.• The second group, 180V240, indicates a wind
shift occurred or it is variable• Calm winds are reported as 00000KT
Wind Direction/Speed Examples
27005KT indicates a wind that is blowing from 270 degrees (i.e. from the west) at a speed of 5 knots
16018G35KT indicates a wind that is blowing from 160 degrees (i.e. from the south-southeast) at a speed of 18 knots with gusts to 35 knots.
Visibility
• Example = 1SM• ‘SM’ is Statute Miles• 10SM would indicate a visibility of 10 statute
miles• 2 1/2SM would indicate a visibility of 2.5
statute miles• M at the beginning would mean less than the
reported number– M1/4SM indicates a visibility of less than 0.25
statute miles
Runway Visual Range
• Example = R11/P6000FT• The first number indicates the runway• Range is given, after the slash, in feet
Present Weather
• Example = -RA BR• The weather occurring at, or in the vicinity of,
the observation point at the time of reporting• There are 5 categories, constructed in
sequences, to consider: Intensity, Descriptor, Precipitation, Obscuration, Other Weather
Present Weather - Intensity
• Example = -RA BR• Intensity: -, +, VC• - = Light (.10”/hour or .01” in 6 minutes)• + = Heavy (.30”/hour or .03” in 6 minutes)• VC = in the vicinity of station• Moderate precip has no symbol
Present Weather - Descriptors
• MI = Shallow• PR = Partial• BC = Patches• DR = Low Drifting• BL = Blowing• TS = Thunderstorm• FZ = Freezing• SH = Shower
Present Weather - Precipitation
• Example = -RA BR• DZ = Drizzle• RA = Rain• SN = Snow• SG = Snow Grains• IC = Ice Crystals• PE = Ice Pellets• GR = Hail• GS = Small Hail/Snow Pellets• UP = Unknown Precip
Present Weather - Obscurations
• Example = -RA BR• BR = Mist• FG = Fog• FU = Smoke• VA = Volcanic Ash• SA = Sand• HZ = Haze• PY = Spray• DU = Widespread Dust
Present Weather - Other
• SQ = Squalls• FC = Funnel Cloud, Tornado or Waterspout• SS = Sandstorm• DS = Duststorm
Present Weather Examples
-TSRA indicates a thunderstorm with light rain.
-RA FG indicates light rain and fog.
Sky Conditions
• Example = SCT060• First three letters represent the amount the
sky is covered• Next three numbers are the height of the
cloud base in hundreds of feet• Up to 3 cloud layers may be reported to a
height of 12,000 feet
Sky Conditions Cont.
FEW indicates 1/8 to 2/8 sky coverage.SCT indicates 3/8 to 4/8 sky coverage.BKN indicates 5/8 to 7/8 sky coverage.OVC indicates 8/8 sky coverage.CLR indicates clear conditions
Sky Conditions Example
SCT060 indicates 3/8 to 4/8 sky (scattered) coverage by a layer of clouds at 6000 feet above the surface.
BKN039 OVC100 indicates 5/8 to 7/8 (broken) sky coverage at 3900 feet and 8/8 (overcast) sky coverage at 10,000 feet.
Temperature/Dewpoint
• Example = 06/04• Temperature is given first, followed by the
dewpoint. Both are rounded to the nearest whole Celsius degree
• Negative readings are coded with a ‘M.’ Example, 01/M01 is temp = 1C, dew = -1C
Altimeter
• Example = A2990• Always coded with an ‘A’• Given in inches of mercury• It is the barometric pressure of the location if
it were at sea level• A2990 = 29.90 inches of mercury
The Remarks Section
• Added only when appropriate• Up to 26 different items can be reported in
this section• ‘RMK’ indicates the beginning of the Remarks
section
Example Remarks
• TORNADO B13 6 NE– Means a tornado began 13 minutes after the hour
and was located 6 miles northeast of the station• PK WND 20032/25– Indicates the strongest (peak) wind since the last
observation– Direction (200), speed of gust (32 knots) and time
of gust (25)
Example Remarks
• Precip Start/Stop Times– RAB07– Coded with type of precip, followed by a B for
began or E for ended– Last numbers indicate minute of the hour the
precip began/end– May be coded together (RAB07E24) indicates
rain began at 7 after and ended at 24 after the hour
Example Remarks
• Sea Level Pressure– SLP125– Given in millibars– SLP stands for sea-level pressure, followed by the last
three digits of the reading– A decimal point is placed between the last two digits– Rule of thumb: If the number is less than 500, place a
10 in front. If more than 500, place a 9 in front– SLP125 1012.5 mb– SLP955 995.5 mb
Example Remarks
• Hourly Precip Amount– P0003– Given in hundredths of an inch. Amount recorded since
the last observation– Trace of precip is reported as P0000
• 6-Hour Precip– Similarly to hourly, but 60009
• 24-Hour Precip– Coded with a 7 in front 70009– Reported at 12Z, amount recorded in last 24 hours
Example Remarks
• Precise Temp/Dewpoint– T00640036– Exact temperature and dewpoint reading to the
tenth of a degree– Begins with a T followed by two 4 digits groups, the
first is temp and the second is dewpoint– The first digit is always the sign; if 0, then the
reading is positive, if 1, then it is negative– In the example, the exact temp = 6.4 degrees C and
dewpoint = 3.6 degrees C