If you're facing a line of thunderstorms, taking a longer deviation around the upwind side of the storm might be a good idea. Here's why...

1) Turbulence Avoidance

Generally speaking, you'll find the best chance for clear, smooth air on the upwind side of a thunderstorm. That's in part because the air is less disturbed by the convection found within the storm, and spreading out downwind.

2) Precipitation Falls On The Downwind Side Of The Anvil

As winds aloft blow the thunderstorm downwind, the anvil begins to spread out. Precipitation usually falls on the downwind side, and odds are you won't find conditions nearly as clear.

3) Clear-Air Hail

Many pilots have experienced hail by flying beneath overhanging anvil clouds. This hail produced in the core of the storm, and then spit out in the direction of the wind.

4) Other Hazards Occur Downwind Too

Severe or extreme turbulence, lightning, and strong straight-line winds can exist outside of the visible thunderstorm. Most of the time, these elements occur downwind of the thunderstorm, in the direction of its movement.

5) Fuel Planning Becomes Difficult

If you're planning to fly down the line of storms and cross around the downwind side, the storm direction isn't working in your favor. A deviation can get much longer than planned as you try to find a clear spot, leading to fuel constraints.

If you approach a line of storms and you're faced with a "should I turn right or left?" moment, turning toward the upwind route is typically the best decision.

Have you faced this decision before? Tell us about it in the comments below.