FAA Aircraft Dispatcher (ADX)MeteorologyHard
A dispatcher receives a report of a sudden wind shift, temperature drop, and gusty surface winds occurring well ahead of an approaching thunderstorm, outside the area of precipitation. This surface boundary is best identified as a:
- ACold front
- BSquall line
- CGust front
- DDry line
Show answer & explanationAnswer & explanation
Correct answer: C. Gust front
A gust front is the leading edge of cool, outflow air from a thunderstorm's downdraft, producing a sudden wind shift, temperature drop, and gusty winds ahead of the storm, distinct from a synoptic-scale cold front.
Why the other options are wrong
- A. A cold front is a synoptic-scale boundary between air masses, not a thunderstorm-generated outflow feature.
- B. A squall line is a line of thunderstorms itself, not the outflow boundary ahead of a single storm.
- D. A dry line separates air masses of differing moisture content, not primarily wind-shift and temperature-drop from a storm.
Gust Front
The leading edge of cool, gusty outflow air spreading out from a thunderstorm's downdraft, often producing a sudden wind shift and temperature drop ahead of the storm.
- Caused by thunderstorm downdraft outflow reaching the surface
- Can occur well ahead of the parent storm and its precipitation
- Often marked by a shelf cloud or roll cloud at the leading edge
Memory trick: Gust front = the storm's cold breath rushing out ahead of it.