What minimum distance should an aircraft maintain from a thunderstorm on approach?

• A. 2 miles
• B. 3 miles
• C. 5 miles
• D. 1 mile

Answer: (B)

Thunderstorms bring strong updrafts, gust fronts, and wind shear that can appear with little warning and rapidly change the flight path. On approach, you want to stay out of the storm’s most hazardous zone, including the gust front and outer fringe where turbulence can still be significant. The minimum distance to keep from a thunderstorm is three miles. Keeping at least this buffer reduces the risk of encountering strong turbulence or microbursts that can occur near the storm edge. Closer than that—one or two miles—places you in areas with much higher and more unpredictable forces. While a larger separation, like five miles, would be safer, three miles is the smallest distance that still provides a practical margin. If a thunderstorm blocks your approach path, divert and follow ATC guidance to maintain safety.