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METAR/TAF The International

Weather Code

By Bob Jackson,MIC, ZSE CWSU

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A ‘METAR’ is a ‘surface’

weather observation

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‘TAF’ is a Terminal Aviation Forecast

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• 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

Order of Informationin METAR:

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Order of Information in METAR:

METAR KSEA 101955Z 20015KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132

What

WhereMetar

orSpeci

When Wind Vis Wx Sky

Clr

Up to 3cloud layers

TempDp

Alt Remarks

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

WHAT - Report name/type• METAR = Hourly Observation• Speci = Special Observation

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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’

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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

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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.

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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

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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

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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

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

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

North

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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

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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.

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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

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

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

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

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

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

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

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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

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

Given in Intensity ( -, ‘ ‘ , +)• Descriptor (SH, TS, FZ, etc)• Precip type (DZ, RA, SN)• Obscuration (FG, BR FU, etc)• Other (dust, funnel cloud)

Present Weather

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

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

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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

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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

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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

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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

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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.

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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.

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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)

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A Simple Temperature Conversion:

• F = (2 * C) + 30• Example:• 10C = 2*10 =20

+ 30 F = 50

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METAR KSEA A02 101955Z 2015G25KT 3/4SM TSRA OVC010CB 19/06 A2992 RMK SLP132=

• A = Inches of Mercury• Q = Hectopascals (Millibars)

Altimeter Setting

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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.

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Order of Information in METAR:

Where When Wind Vis Wx Sky

Clr

Up to 3cloud layers

TempDp

Alt RemarksWhat

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‘TAF’ is a Terminal Aviation Forecast

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TAF KSEA 101919Z 20015KT P6SM SCT010BKN030 TEMPO 20015G25KT 3/4SMTSRA OVC010CBBCMG 0304 VRB05 SCT040 BKN100=

• WHAT - TAF

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TAF KSEA 101919Z 20015KT P6SM SCT010BKN030 TEMPO 20015G25KT 3/4SMTSRA OVC010CBBCMG 0304 VRB05 SCT040 BKN100=

• WHAT - TAF • WHERE - Same as METAR

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TAF KSEA 101919Z 20015KT P6SM SCT010BKN030 TEMPO 20015G25KT 3/4SMTSRA OVC010CBBCMG 0304 VRB05 SCT040 BKN100=

• WHAT - TAF • WHERE - Same as METAR• WHEN - Date/time of

beginning/ending

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TAF KSEA 101919Z 20015KT P6SM SCT010BKN030 TEMPO 20015G25KT 3/4SMTSRA OVC010CBBCMG 0304 VRB05 SCT040 BKN100=

• WIND - Same as METAR

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TAF KSEA 101919Z 20015KT P6SM SCT010BKN030 TEMPO 20015G25KT 3/4SMTSRA OVC010CBBCMG 0304 VRB05 SCT040 BKN100=

• VISIBILITY - ‘Somewhat’ the same as METAR– Forecast up to 6 miles. – If more than 6 miles then ‘P’ (plus) is

added.

• WIND - Same as METAR

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TAF KSEA 101919Z 20015KT P6SM SCT010

BKN030 TEMPO 20015G25KT 3/4SM

TSRA OVC010CBBCMG 0304 VRB05 SCT040

BKN100=• WEATHER - Same as METAR

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TAF KSEA 101919Z 20015KT P6SM SCT010BKN030 TEMPO 20015G25KT 3/4SMTSRA OVC010CBBCMG 0304 VRB05 SCT040 BKN100=

• WEATHER - Same as METAR• CLOUDS - Same as METAR

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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

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Amendments are made as needed.

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This is notThe End