The best advice: don’t.
Don't fly in thunderstorms. Don't fly close to
thunderstorms. Don't fly under thunderstorms and, in
almost all cases, don't try to fly over thunderstorms.
"I'm beginning to see signs that the two governments
are increasing the pace of their dialogue, and I'm supportive of
that."
Source: Boeing CEO Jim McNerney, speaking to
reporters in Paris about possible progress and easing of tensions
between the US and European Union in their politely contentious
battle over aircraft trade subsidies.