FAA Private Pilot Airplane (PAR)Weather Theory and ServicesMedium
A pilot reviewing surface analysis notices a front where the weather shows a mix of both cold-front and warm-front characteristics — an area of continuous precipitation ahead of the front along with a narrow band of showery precipitation embedded within it, and the temperature pattern does not cleanly match either front type. This is best classified as a(n):
- ASquall line
- BStationary front
- CDryline
- DOccluded front
Show answer & explanationAnswer & explanation
Correct answer: D. Occluded front
An occluded front forms when a fast-moving cold front overtakes a slower warm front, lifting the warm air aloft and producing a mixture of both frontal weather types, including areas of continuous and showery precipitation. Stationary fronts show little movement, drylines separate moist and dry air masses, and squall lines are narrow bands of thunderstorms, not full frontal systems.
Why the other options are wrong
- A. A squall line is a line of thunderstorms, not a full synoptic-scale front.
- B. Stationary fronts do not show significant movement or the mixed characteristics described.
- C. A dryline separates dry and moist air masses, unrelated to frontal occlusion.
Occluded Front
An occluded front occurs when a faster-moving cold front catches up to and overtakes a slower warm front, lifting the warm air mass off the ground and combining features of both front types.
- Cold occlusion: cold air behind front is colder than air ahead
- Warm occlusion: cold air behind front is warmer than air ahead
- Produces complex, mixed weather patterns
Memory trick: Occlusion = fronts collide and combine