FAA Airline Transport Pilot (ATM)Meteorology and Weather ServicesHard
A dispatcher is briefing a crew on a fast-moving squall line ahead of an approaching cold front. Which hazard is most characteristic of squall lines?
- AWidespread light-to-moderate stratiform precipitation with stable air
- BSmooth, non-turbulent air with isolated virga
- CA narrow band of severe thunderstorms producing damaging winds, large hail, and possible tornadoes
- DPersistent low ceilings and fog with little wind
Show answer & explanationAnswer & explanation
Correct answer: C. A narrow band of severe thunderstorms producing damaging winds, large hail, and possible tornadoes
A squall line is a narrow band of active, often severe thunderstorms that can form ahead of a cold front. Squall lines are known for producing some of the most severe weather hazards, including damaging straight-line winds, large hail, heavy rain, and tornadoes, developing with little advance warning.
Why the other options are wrong
- A. Squall lines are convective and unstable, not stratiform and stable.
- B. Squall lines produce significant turbulence, not smooth air.
- D. Fog and low ceilings are not characteristic of the violent convective nature of squall lines.
Squall Line
A narrow band of active thunderstorms, often forming ahead of a cold front, capable of producing severe weather with little warning.
- Can develop 50–300 miles ahead of a cold front
- Produces severe turbulence, hail, damaging winds, and tornadoes
- More hazardous than the parent cold front itself
Memory trick: A squall line is the storm's angry advance guard, striking hard before the front arrives