FAA Commercial Pilot Airplane (CAX)WeatherEasy
A pilot observes a rapidly developing thunderstorm with a distinct anvil top and virga beneath its base. What does the presence of virga indicate about the precipitation?
- AHeavy rain is reaching the surface in the immediate vicinity.
- BThe storm is dissipating and no longer poses a threat.
- CHail is falling from the thunderstorm.
- DPrecipitation is evaporating before reaching the ground.
Show answer & explanationAnswer & explanation
Correct answer: D. Precipitation is evaporating before reaching the ground.
Virga is precipitation that falls from a cloud but evaporates before reaching the ground. It appears as streaks or wisps extending downward from the cloud base. While it indicates precipitation within the cloud, it confirms that it is not reaching the surface.
Why the other options are wrong
- A. Incorrect. Virga explicitly means precipitation is *not* reaching the surface.
- B. Incorrect. Virga can occur at any stage of a thunderstorm and does not necessarily mean it's dissipating or no longer a threat. Downbursts can occur even with virga.
- C. Incorrect. While thunderstorms can produce hail, virga itself only indicates evaporation of precipitation, not the type of precipitation.
Virga
Virga is precipitation that falls from a cloud but evaporates or sublimes before reaching the ground. It appears as streaks or wisps extending below the cloud base.
- Precipitation that does not reach the ground.
- Appears as streaks or wisps from cloud base.
- Can be associated with strong downdrafts (microbursts).
- Common in dry atmospheric layers below clouds.
Memory trick: Virga: Vaporizing Rain, Ground-Avoided.