FAA Sport Pilot Airplane (SPA)WeatherMedium
A weather briefer advises that a non-frontal, narrow band of active thunderstorms is developing ahead of an approaching cold front and is expected to produce severe weather. What is this line of thunderstorms called?
- AA stationary front
- BA squall line
- CAn occluded front
- DA dry line
Show answer & explanationAnswer & explanation
Correct answer: B. A squall line
A squall line is a narrow, non-frontal band of active thunderstorms that often forms ahead of a fast-moving cold front and can produce severe turbulence, hail, and damaging winds, sometimes more severe than the front itself.
Why the other options are wrong
- A. A stationary front is a boundary with little movement, not a line of thunderstorms.
- C. An occluded front occurs when a cold front overtakes a warm front, a different phenomenon.
- D. A dry line separates air masses of differing moisture content, not necessarily linked to thunderstorm bands ahead of a front.
Squall Line
A squall line is a narrow, non-frontal band of active thunderstorms that frequently forms ahead of a fast-moving cold front, capable of producing severe turbulence, hail, and damaging straight-line winds.
- Non-frontal but often precedes a cold front
- Can produce severe/organized convective weather
- One of the most hazardous weather phenomena to aviation
Memory trick: Squall line: the storm's 'advance guard' racing ahead of the cold front.