TAF - Terminal Area Forecast - Issued 4 times daily (0000Z – 0600Z – 1200Z – 1800Z)
A TAF functions in much the same way a METAR does, but instead of current observations it is a forecast for a 24 hour period. They are meteorological forecast for 5 statue miles around an airport. They use the exact same weather codes as a METAR and have a very similar format (For more on METAR’s check out our METAR Page). Below is an example of a TAF:

AMD KCGI 090309Z 0903/0924 22010KT P6SM BKN005 OVC020
TEMPO 0903/0904 24015G25KT 3SM -SHRA BR OVC002
FM090400 23018G30KT P6SM OVC015
FM091200 26020G35KT P6SM OVC025
FM092000 28012G22KT P6SM BKN025

The ‘AMD’ prefixed to the station identifier means that this TAF has been amended since it’s original issuance. Just like a METAR, the first line starts out with the station identifier and time/date of the issuance. The first line of a TAF is also shows the current meteorological conditions at the time of observation. Breaking it down line by line:
0903/0924 - Valid Period: Valid the 9th day of the month at 0300z until the 9th day of the month at 2400Z.
22010KT – Current Wind: 220° at 10 knots.
P6SM – Current Visibility: Better than 6 statue miles (P stands for ‘better than’).
BKN005 OVC020 - Cloud Cover: Broken at 500 feet AGL and overcast at 2,000 feet AGL.
TEMPO 0903/0904 – Temporary Forecast Conditions: The following conditions are forecasted to be temporary between 0300Z on the 9th day of the month and 0400Z on the 9th day of the month.
24015G25KT – Forecasted Wind: The wind is forecasted to be 240° at 15 knots gusting up to 25 knots.
3SM - Visibility Forecast: 3 statue miles.
-SHRA BR -  Weather Forecast: Light rain showers and mist
OVC002 – Cloud Forecast: Overcast at 200 feet.
FM090400 – Forecast Period: The next weather forecast will begin at 0400Z on the 9th day of the month.
…

As you can see, METAR and TAF’s are very similar with the same layout and same weather codes.  The proper way to read a TAF forecast is like follows:

FM092000 28012G22KT P6SM BKN025

Begining at 2000Z on the 9th, winds out of 280° at 12 knots gusting up to 22 knots, visibility better than 6 statue miles, clouds broken at 2,500 feet.

TAF’s can also show probability of conditions in forecasts. If you see a line as follows:

PROB30 1215 1SM +TSRA

You would read that as:

There is a 30% chance between 1200Z and 1500Z for viability of 1 statue mile in heavy thunderstorms.

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Resources: For more detailed information, check out the FAA published book: Aviation Weather Services. This book contains all the information about every weather service available for pilots. This book is a valuable resource when it comes to studying for checkrides or trying to decipher the more uncommon weather products. Click on the book below to find out more.