FAA Instrument Flight Instructor (FII)WeatherEasy
A CFII briefs an instrument student that a warm front is forecast to move through the departure airport during the planned cross-country flight. Ahead of the warm front's surface position, the student should expect which weather conditions?
- ARapid clearing with a shift to cooler, drier air
- BScattered towering cumulus with brief, heavy showers and gusty winds
- CLow ceilings, poor visibility, and steady precipitation in widespread stratiform clouds
- DClear skies with light and variable winds
Show answer & explanationAnswer & explanation
Correct answer: C. Low ceilings, poor visibility, and steady precipitation in widespread stratiform clouds
Warm fronts have a gently sloping frontal surface, so warm moist air is lifted gradually over the retreating cold air well ahead of the surface position. This produces widespread stratus and nimbostratus clouds, low ceilings, poor visibility, and steady precipitation that can persist for many hours.
Why the other options are wrong
- A. Rapid clearing occurs behind a cold front, not ahead of a warm front.
- B. Towering cumulus and brief heavy showers are typical of a fast-moving cold front, not a warm front.
- D. Clear skies are not expected ahead of an approaching warm front with moist air being lifted.
Warm Front Weather
A warm front occurs where warm air advances over retreating cooler air along a gently sloping boundary, producing widespread low stratiform clouds and steady precipitation well ahead of the surface position.
- Gentle frontal slope (about 1:100)
- Widespread stratus/nimbostratus and fog
- Steady precipitation lasting hours
- Poor visibility common near the surface
Memory trick: Warm front = slow, wide, wet blanket of clouds