FAA Private Pilot Helicopter (PRH)WeatherMedium
A pilot reviews the following TAF: 'TAF KABC 0912Z 0912/0918 21015KT 5SM HZ SCT025 BECMG 0914/0916 25020G30KT P6SM SKC'. According to this forecast, what conditions are expected to be established at KABC by 1600Z?
- AWind 210° at 15 knots, visibility 5 statute miles, haze
- BWind 250° at 20 knots gusting to 30 knots, visibility greater than 6 statute miles, sky clear
- CNo significant change is expected through the forecast period
- DWind 250° gusting to 30 knots, visibility 5 statute miles, haze persisting
Show answer & explanationAnswer & explanation
Correct answer: B. Wind 250° at 20 knots gusting to 30 knots, visibility greater than 6 statute miles, sky clear
The BECMG (becoming) group '0914/0916' indicates a gradual change beginning at 1400Z and completing by 1600Z. By 1600Z the new conditions—wind 250° at 20 knots gusting 30, visibility greater than 6 statute miles (P6SM), and sky clear (SKC)—are established.
Why the other options are wrong
- A. These are the initial conditions at 0912Z, not the conditions after the BECMG change.
- C. The BECMG group specifically forecasts a significant change in wind, visibility, and sky condition.
- D. Haze clears with the improving visibility; it does not persist after the BECMG completes.
TAF Change Group: BECMG
BECMG (becoming) indicates a gradual, permanent change in conditions expected to occur within the specified time range, with new conditions in effect by the end time.
- Time range format is DDHH/DDHH (day/hour to day/hour)
- Change is gradual, not instantaneous
- Conditions after the end time are as forecast in the BECMG group
Memory trick: 'FM flips fast, BECMG builds gradually, TEMPO is temporary, PROB is a probability'