FAA Aircraft Dispatcher (ADX)MeteorologyEasy
A dispatcher reviewing radar imagery notices a narrow, continuous line of active, sometimes severe thunderstorms forming 50 to 100 miles ahead of and parallel to an advancing cold front. What is this line of storms called?
- AA frontal wave
- BAn occluded front
- CA squall line
- DA dry line
Show answer & explanationAnswer & explanation
Correct answer: C. A squall line
A squall line is a narrow band of active thunderstorms, often producing severe weather such as damaging winds, hail, and occasionally tornadoes, that forms ahead of and roughly parallel to an advancing cold front. It is a distinct feature from the front itself.
Why the other options are wrong
- A. A frontal wave is a disturbance along a stationary or slow-moving front that can develop into a low-pressure system, not a line of storms.
- B. An occluded front is a frontal boundary type where a cold front overtakes a warm front, not a line of thunderstorms.
- D. A dry line is a boundary separating moist and dry air masses, typically in the central U.S., not necessarily tied to a cold front.
Squall Line
A narrow, continuous line of active, often severe thunderstorms that forms ahead of and roughly parallel to an advancing cold front.
- Can produce severe wind gusts, large hail, and tornadoes
- Forms independently of but associated with cold front passage
- Often more intense than the weather along the front itself
Memory trick: Squall line = the cold front's 'advance guard' of storms marching ahead of it.