TAF - NM or SM

meritflyer

Well-Known Member
Just brushing up on my aviation knowledge here.

In Everything Explained for the Professional Pilot it describes the TAF as having a 5 nm radius. However, I believe the AIM says 5 sm.

Anyone have an AIM handy that can help out?
 
Just brushing up on my aviation knowledge here.

In Everything Explained for the Professional Pilot it describes the TAF as having a 5 nm radius. However, I believe the AIM says 5 sm.

Anyone have an AIM handy that can help out?

7-1-30 in the AIM says SM for visibility...I couldn't see anything about the radius? Maybe I'm not looking close enough, but it'd be my guess since they did vis in sm that would be too.
 
Just brushing up on my aviation knowledge here.

In Everything Explained for the Professional Pilot it describes the TAF as having a 5 nm radius. However, I believe the AIM says 5 sm.

Anyone have an AIM handy that can help out?

I know it's 5sm.. just can't find the where it says that.
 
I know it's 5sm.. just can't find the where it says that.

When developing a TAF the meteorologist focuses on only the forecast area for the product. A TAF's forecast area is traditionally set at a 5sm standard from the center of the aerodrome, however locally defined. However, meteorologist can utilize the Vicinity (VC) remark to indicate conditions that are outside of 5sm, but within 10sm of the center of the aerodrome - although the use of VC tends to be quite liberal to usually emphasize conditions in the local area which at times may be outside of the 10nm ring. Explains of VC's use are VCSH (Rain Showers in the Vicinity), VCTS (Thunderstorms in the Vicinity).

The visibility format is stated in SM though, which is the standard for visibility reporting. Unless of course you're in a region that utilizes the meter system.

I suppose this is another question that could have been tossed into the Meteorology section. If there was one. Make your recommendations to the leadership if you feel it'd be a worthwhile section.
 
Just brushing up on my aviation knowledge here.

In Everything Explained for the Professional Pilot it describes the TAF as having a 5 nm radius. However, I believe the AIM says 5 sm.

Anyone have an AIM handy that can help out?



From AC 00-45F Aviation Weather Services

7.2 Terminal Aerodrome Forecast (TAF)
A Terminal Aerodrome Forecast (TAF) is a concise statement of the expected meteorological conditions significant to aviation for a specified time period within five statute miles (SM) of the center of the airport’s runway complex (terminal). The TAFs use the same weather codes found in METAR weather reports (Section 2) and can be viewed on the National Weather Service (NWS) Aviation Digital Data Service (ADDS) web site at: http://adds.aviationweather.noaa.gov/tafs/.

Pilot's Handbook of Aeronautical Knowledge

Terminal Aerodrome Forecasts (TAF)
A TAF is a report established for the five statute mile radius around an airport. TAF reports are usually given for larger airports. Each TAF is valid for a 30-hour time period, and is updated four times a day at 0000Z, 0600Z, 1200Z, and 1800Z. The TAF utilizes the same descriptors and abbreviations as used in the METAR report. The TAF includes the following information in sequential order:

Terminal aerodrome forecast (TAF). A report established for the 5 statute mile radius around an airport. Utilizes the same descriptors and abbreviations as the METAR report.
 
Now that's interesting.

Suppose I've been out of the game just too long. Either that or it is another one of the differences between civilian and military operational forecast requirements.

Nevertheless, there you go.

edit: nope, I was wrong. Found a copy of our weather forecasting publication, our TAFs were for the forecast area in statute miles as well. (AFMAN 15-124). My original post has been edited with the corrected information.
 
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