Twenty Miles?

The 20-mile clearance policy is a safe number and probably easy to stipulate, but scale and definitions make it challenging. For every fully visible and developed severe thunderstorm, there are even more smaller cells or building storms that may or may not grow to thunderstorm level. Sometimes a curtain of rain is just a curtain of rain. Other times, it can be hiding something much bigger due to the lurking cumulonimbus that has built up above the overcast.

Mike Hart

Sunday, June 24, 2018 at 12:00 AM ET

Verified

Key Takeaways:

Thunderstorms are extremely powerful and constant phenomena, releasing energy comparable to a nuclear bomb, with hazards like turbulence and hail extending up to 20 miles or more from the main storm.
The FAA's 20-mile avoidance recommendation is crucial but challenging to apply in practice, as defining "what" constitutes a thunderstorm's boundary for avoidance is complex and requires pilot experience due to varied storm appearance and radar interpretation.
Pilots must be acutely aware of specific, highly dangerous thunderstorm-related hazards such as gust fronts, virga, and microbursts, which can precede or extend from storms and create severe wind shear, posing critical risks, especially during takeoff and landing.

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Time-lapse thunderstorm videos recorded by the International Space Station always remind me of science fiction movies, slightly unbelievable. The truth is both stranger and more violent than you may realize.

Our planet experiences constant thunderstorms, weather phenomena when solar heat stored in warm, moist air is converted into kinetic and electromagnetic energy, including X-ray and gamma-ray flashes. According to NOAA estimates, there are about 16 million thunderstorms worldwide each year, and roughly 2000 at any given moment.