FAA Private Pilot Airplane (PAR)Weather Theory and ServicesHard
A pilot checks a TAF for the destination airport that was issued at 1200Z and is valid 1212/1312. At 1530Z, actual weather deteriorates well below the forecast conditions, and the pilot notices a new TAF has been issued labeled 'TAF AMD' with a valid period of 1215/1312. What does this indicate?
- AThe original TAF was canceled and no forecast is currently available
- BThe TAF will not be updated again until the next scheduled issuance time
- CThe airport has been closed due to the weather described
- DThe National Weather Service has issued a corrected forecast because actual or expected conditions differ significantly from the original TAF
Show answer & explanationAnswer & explanation
Correct answer: D. The National Weather Service has issued a corrected forecast because actual or expected conditions differ significantly from the original TAF
A TAF is amended (AMD) when observed or expected weather conditions vary significantly from the original forecast, requiring an update to reflect the more accurate outlook. The amended TAF supersedes the original for the remainder of the valid period, but does not indicate cancellation or airport closure.
Why the other options are wrong
- A. An amendment updates a forecast, it does not cancel it entirely.
- B. Amended TAFs can be issued at any time conditions warrant, not just at scheduled times.
- C. TAFs do not determine airport operational status; that is a separate NOTAM or ATC function.
TAF Amendment (AMD)
An amended TAF (labeled 'TAF AMD') is issued when observed or anticipated weather significantly differs from the previously issued forecast, ensuring pilots have the most current information.
- TAFs are routinely issued four times daily and valid for 24 or 30 hours
- Amendments can be issued anytime conditions warrant, superseding the prior TAF
- 'COR' indicates a correction to a TAF containing an error, distinct from 'AMD'
Memory trick: 'AMD Means Amend the Trend' — a new AMD TAF reflects real weather changes.