Thunderstorms

A thunderstorm is the weather hazard that should concern pilots the most because it represents different types of risks. For instance, near and inside a storm, you could encounter low-level wind shears, lighting, hail, icing, severe turbulence, and tornadoes. All those weather phenomena are hazardous for the aircraft and its occupants. For that reason, pilots must avoid thunderstorms at all times.

For a thunderstorm to develop, it is required three conditions moisture, unstable air, and lifting action. Storms form when warm air evaporates water (moisture) and raises (lifting action) because of its less density, disturbing the stability of the environment (unstable air).

Thunderstorms have three stages: the cumulus, mature, and the dissipating stage. Strong updrafts characterize the cumulus stage. Next, the storm takes about 15 minutes to reach the mature stage, where precipitation falls in the form of rain showers or hail, and turbulence is present around the thunderstorm. Updrafts and downdrafts are present. Finally, when liftin action slows down, and the wind changes the cell’s shape into an anvil form, the dissipating stage begins, just downdrafts are present.

References:

Federal Aviation Administration. (2016). AC-00-6B. Retrieved from: https://www.faa.gov/documentlibrary/media/advisory_circular/ac_00-6b.pdf

Federal Aviation Administration. (2016). Pilots handbook of aeronautical knowledge. Washington, D.C.