1. METAR/TAF The International Weather Code
Introduction. I usually try to emphasise that the METAR/TAF system is not difficult, just different from what has been used in the past. As time goes on, the slides mentioning the FTs and SAOs will be deleted.
By Bob Jackson,
MIC, ZSE CWSU

2. A ‘METAR’ is a ‘surface’ weather observation
This shows that the products still exist, just with a different name and format.

3. ‘TAF’ is a Terminal Aviation Forecast
This shows that the products still exist, just with a different name and format.

4. Order of Information in METAR: What - Type of product
Where - Station Name
Who Used if automated
When Date and Time of METAR
Wind Given in Degrees ‘true North’
Weather - Present weather
Remarks - Additional comments as needed
A simplified view of the order of presentation of the METAR.

5. Order of Information in METAR:
What
Clr
Metar or
Speci
Sky
Temp Dp
Where
When
Wind
Vis Wx
Alt
Remarks
Up to 3
cloud layers
METAR
KSEA
101955Z
20015KT
3/4SM
TSRA
OVC010CB
19/06
A2992
RMK SLP132
A simplified view of the order of presentation of the METAR.

6. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132 =
WHAT - Report name/type
METAR = Hourly Observation
Speci = Special Observation

7. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132 =
WHERE - Four Letter station ID.
48 States begin with ‘K’
Alaskan stations begin with ‘PA’
Hawiian stations begin with ‘PH’

8. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132 =
WHO - Not used if Human Obs.
A01 - For AWOS Observation
A02 - For ASOS Observation

9. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132 =
WHEN - Date and Time the of OBS was taken in UCT.

10. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WHEN - Date and Time the of OBS was taken in UCT.
Date of OBS

11. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132 =
WHEN - Date and Time the of OBS was taken in UCT.
Date of OBS
Hour of the day

12. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WHEN - Date and Time the of OBS was taken in UCT.
Date of OBS
Hour of the day
Minute

13. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WIND

14. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WIND
First 3 digits = Direction in True North

15. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WIND -
First 3 digits = Direction in True North
4th & 5th digits = Wind Speed

16. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WIND -
First 3 digits = Direction in True North
4th & 5th digits = Wind Speed
‘G’ indicates gusts and speed.

17. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WIND -
First 3 digits = Direction in True North
4th & 5th digits = Wind Speed
‘G’ indicates gusts.
KT = Speed given in Knots

18. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WEATHER

19. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WEATHER
Visibility

20. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WEATHER
Visibility
Present Weather

21. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WEATHER
Visibility
Present Weather
Sky cover (Clouds)

22. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WEATHER
Visibility
Present Weather
Sky cover (Clouds)
Temp/DP

23. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
WEATHER
Visibility
Present Weather
Sky cover (Clouds)
Temp/DP
Altimeter

24. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
VISIBILITY
Reported in Statute Miles (SM) and fractions up to 6 miles

25. METAR KSEA A02 101955Z 20015G25KT 3/4SM -TSRA OVC010CB 19/06 A2992 RMK SLP132=
Present Weather
Given in Intensity ( -, ‘ ‘ , +)
Descriptor (SH, TS, FZ, etc)
Precip type (DZ, RA, SN)
Obscuration (FG, BR FU, etc)
Other (dust, funnel cloud)

26. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
Clouds and Cloud Height

27. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
Clouds and Cloud Height
Coverage (FEW, SCT, BKN, OVC)

28. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
Clouds and Cloud Height
Coverage (FEW, SCT, BKN, OVC)
Height - Given in feet AGL

29. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
Clouds and Cloud Height
Coverage (FEW, SCT, BKN, OVC)
Height - Given in feet AGL
Type - IF convective clouds present

30. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
Clouds and Cloud Height
Coverage (FEW, SCT, BKN, OVC)
Height - Given in feet AGL
Type - IF convective clouds present
CB = Cumulonimbus

31. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
Clouds and Cloud Height
Coverage (FEW, SCT, BKN, OVC)
Height - Given in feet AGL
Type - IF convective clouds present
CB = Cumulonimbus
TCU = Towering Cu

32. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA BR BKN000 OVC010CB 19/06 A2992 RMK SLP132=
If the sky is PARTIALLY obscured, then a surface based cloud (Fog) height is given as “000”.
In example, the first layer is a surface based obscuration due to rain and fog.

33. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA VV04 19/06 A2992 RMK SLP132=
If the sky is Totally Obscured then, VV = Vertical Vibility in 100s of feet.
In this example:
VV004 = The sky is obscured, and the Vertical Visibility is 400 ft.

34. METAR KSEA A02 101955Z 20015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
Temperature/Dew Point
Given in degrees Celsius
If preceded by ‘M’ then is minus ( <0)

35. A Simple Temperature Conversion:
F = (2 * C) + 30
Example:
10C = 2*10 = F = 50

36. METAR KSEA A02 101955Z 2015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=
Altimeter Setting
A = Inches of Mercury
Q = Hectopascals (Millibars)

37. METAR KSEA A02 101955Z 2015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132 VIS N2 WSHIFT 30 FROPA=
REMARKS - significant items not included in the main body of the METAR.
SLP = Sea Level Pressure in Millibars
Visibility to the North is 2 miles.
The wind shifted at 30 min past the hour because of a frontal passage.

38. Order of Information in METAR:
Clr
Sky
Temp Dp
What
Where
When
Wind
Vis Wx
Alt
Remarks
Up to 3
cloud layers
A simplified view of the order of presentation of the METAR.

39. ‘TAF’ is a Terminal Aviation Forecast
This shows that the products still exist, just with a different name and format.

40. TAF KSEA 101919Z 20015KT P6SM SCT010. BKN030 TEMPO 20015G25KT 3/4SM
TAF KSEA Z KT P6SM SCT010 BKN030 TEMPO G25KT 3/4SM TSRA OVC010CB BCMG VRB05 SCT040 BKN100=
WHAT - TAF

41. WHAT - TAF WHERE - Same as METAR
TAF KSEA Z KT P6SM SCT010 BKN030 TEMPO G25KT 3/4SM TSRA OVC010CB BCMG VRB05 SCT040 BKN100=
WHAT - TAF
WHERE - Same as METAR

42. WHEN - Date/time of beginning/ending
TAF KSEA Z KT P6SM SCT010 BKN030 TEMPO G25KT 3/4SM TSRA OVC010CB BCMG VRB05 SCT040 BKN100=
WHAT - TAF
WHERE - Same as METAR
WHEN - Date/time of beginning/ending

43. TAF KSEA 101919Z 20015KT P6SM SCT010. BKN030 TEMPO 20015G25KT 3/4SM
TAF KSEA Z KT P6SM SCT010 BKN030 TEMPO G25KT 3/4SM TSRA OVC010CB BCMG VRB05 SCT040 BKN100=
WIND - Same as METAR

44. VISIBILITY - ‘Somewhat’ the same as METAR
TAF KSEA Z KT P6SM SCT010 BKN030 TEMPO G25KT 3/4SM TSRA OVC010CB BCMG VRB05 SCT040 BKN100=
WIND - Same as METAR
VISIBILITY - ‘Somewhat’ the same as METAR
Forecast up to 6 miles.
If more than 6 miles then ‘P’ (plus) is added.

45. TAF KSEA 101919Z 20015KT P6SM SCT010. BKN030 TEMPO 20015G25KT 3/4SM
TAF KSEA Z KT P6SM SCT010 BKN030 TEMPO G25KT 3/4SM TSRA OVC010CB BCMG VRB05 SCT040 BKN100=
WEATHER - Same as METAR

46. WEATHER - Same as METAR CLOUDS - Same as METAR
TAF KSEA Z KT P6SM SCT010 BKN030 TEMPO G25KT 3/4SM TSRA OVC010CB BCMG VRB05 SCT040 BKN100=
WEATHER - Same as METAR
CLOUDS - Same as METAR

47. Significant Weather Changes
FMnn = Change expected at that time
PROBnn = Probability of occurrance
TEMPO = Expected change for less than 1hr and less then 1/2 of the period.
BECMG = Condition change at the time indicated

48. Amendments are made as needed.

49. This is not The End