FAA Ground School Practice Test

The presence of ice pellets at the surface is evidence that there:

1. Is a temperature inversion with freezing rain at a higher altitude

2. Are strong thunderstorms nearby

3. Is clear air above the surface

4. Is a rapid drop in temperature

The correct answer is: Is a temperature inversion with freezing rain at a higher altitude

The presence of ice pellets at the surface indicates that a temperature inversion is occurring, coupled with freezing rain aloft. This phenomenon occurs when warmer air is trapped above a layer of colder air at or near the surface. As precipitation falls from the warmer air aloft, it may start as rain but will freeze into ice pellets upon passing through the colder air close to the ground. This is a critical weather pattern to recognize, as it often leads to hazardous conditions for aviation, such as slick runways and reduced visibility. In contrast, strong thunderstorms do not typically produce ice pellets, as they are associated with warm, moist air that can lead to rain. The presence of clear air above the surface does not correlate with ice pellets since there would need to be higher, warmer temperatures for ice pellets to form. Lastly, a rapid drop in temperature might contribute to freezing conditions but is not the direct cause of ice pellets; the specific layering of temperature that results in a temperature inversion is the key factor in forming ice pellets.