1. ATS/ESS 452: Synoptic Meteorology
METAR
The Station Model

2. 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

3. Example
KHSV Z 22010KT 3SM -RA BR OVC010 09/08 A2969 RMK AO2 RAB01E11B45 CIG 007V012 SLP053 P0000 T
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

4. Web Resources
Station ID Look-up: Federal Meteorological Handbook Chapter on METAR:

5. 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

6. 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.

7. 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

8. 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

9. 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.

10. 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

11. Runway Visual Range Example = R11/P6000FT
The first number indicates the runway
Range is given, after the slash, in feet

12. 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

13. 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

14. Present Weather - Descriptors
MI = Shallow
PR = Partial
BC = Patches
DR = Low Drifting
BL = Blowing
TS = Thunderstorm
FZ = Freezing
SH = Shower

15. 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

16. Present Weather - Obscurations
Example = -RA BR
BR = Mist
FG = Fog
FU = Smoke
VA = Volcanic Ash
SA = Sand
HZ = Haze
PY = Spray
DU = Widespread Dust

17. Present Weather - Other
SQ = Squalls
FC = Funnel Cloud, Tornado or Waterspout
SS = Sandstorm
DS = Duststorm

18. Present Weather Examples
-TSRA indicates a thunderstorm with light rain. -RA FG indicates light rain and fog.

19. 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

20. 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

21. 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.

22. 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

23. 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 = inches of mercury

24. 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

25. Example Remarks TORNADO B13 6 NE PK WND 20032/25
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)

26. 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

27. 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  mb
SLP955  mb

28. Example Remarks Hourly Precip Amount 6-Hour Precip 24-Hour Precip
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

29. 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