Terminal Aerodrome Forecast (TAF)

Private Pilot License (PPL) Notes

This section explains the Terminal Aerodrome Forecast (TAF), how to read and interpret it, and how to access TAFs using online resources and aviation apps.

What is a Terminal Aerodrome Forecast (TAF)?

1. A coded, text-based weather forecast for specific airports.
2. Issued for larger airports in the U.S.
3. Covers expected conditions within a 5-mile radius of the airport.
4. Includes forecasts of wind, visibility, precipitation, obstructions to vision, and cloud coverage.
5. Issued four times daily and amended as necessary.
6. Covers a period of 24 hours; some TAFs cover 30 hours for major airline airports.

Understanding TAF Components

1. TAFs follow a specific order in presenting information, similar to METARs.
2. If your departure or arrival airport doesn't have a TAF:
   1. Review forecasts for nearby airports to get an idea of expected conditions.
3. Use the "Where, When, Wind" technique to decode TAFs, as with METARs.

Decoding a TAF Example

1. Example TAF for Shreveport, Louisiana:
   1. First six digits: Day of the month and Zulu (UTC) time the forecast was issued.
      1. E.g., "191722Z" means issued on the 19th day at 1722 Zulu.
   2. Next group defines the valid period of the forecast:
      2. E.g., "1918/2018" means valid from 1800 Zulu on the 19th to 1800 Zulu on the 20th.
   3. Wind forecast:
      1. Format is the same as in METARs.
      2. E.g., "11006KT" means wind from 110 degrees at 6 knots.
   4. Visibility forecast:
      1. "P6SM" means visibility greater than six statute miles.
   5. Cloud coverage forecast:
      1. "SCT040 BKN070 OVC250" means scattered clouds at 4,000 ft, broken at 7,000 ft, overcast at 25,000 ft.
   6. Forecast changes indicated by time groups and terms like "FM" (from), "TEMPO" (temporary), "PROB" (probability):
      2. E.g., "FM2100" indicates a change starting at 2100 Zulu.
      3. "TEMPO 2100/2400" indicates temporary conditions between 2100 and 2400 Zulu.
      4. "PROB30" indicates a 30% probability of specified conditions.
   7. "TEMPO" indicates conditions lasting less than one hour at a time and totaling less than half the indicated period.
2. Additional information:
   8. Military TAFs may include barometric pressure and temperature forecasts.
   9. "BECMG" indicates gradual changes expected during a specified period.
   10. "AMD" indicates an amended TAF when conditions change rapidly.

Accessing TAFs

1. TAFs can be accessed via the web or aviation apps:
   1. Example websites: Aviation Weather Center at aviationweather.gov.
   2. Example apps: ForeFlight for iPhone and iPad.
2. Accessing TAFs on the Aviation Weather Center website:
   1. Select "Graphical Forecasts for Aviation" (GFA).
   2. Configure map options to include TAFs:
      1. Click "Configure Map Options" > "Data" > "METAR" tab.
      2. Enable "Include TAF".
   3. Click on an airport to view METAR and TAF.
   4. Access TAF data directly via the "Products" menu.
3. Accessing TAFs in the ForeFlight app:
   1. Go to the "Airports" page and enter the airport ID.
   2. Select the "Weather" tab, then "TAF" to view current TAFs in standard and decoded formats.
   3. On the interactive map, tap an airport to view METAR and TAF.
   4. Useful for reviewing TAFs along your route and at your destination.

Key Points to Remember

1. Forecasts are not perfect; pilots must understand their limitations:
   1. Short-range forecasts are generally more accurate than long-range forecasts.
   2. Newer forecasts are more accurate than older ones.
   3. Forecasts of good weather are usually more accurate than forecasts of bad weather.
2. Always check the most recent TAFs before flight planning.
3. Be aware of any amendments ("AMD") to TAFs indicating significant changes.
4. Understand how to decode TAFs to make informed decisions.

By mastering TAFs, you will enhance your ability to plan flights safely and anticipate weather conditions at your departure and arrival airports.