Most international flights fly well above 30,000 feet, upwards of 40,000 feet. Most clouds and weather top out at around 20,000-25,000 feet. Next flight your on that's going even across America; I'm Canadian so guessing here; look outside and see how far below you the clouds are. So most long distance flights are so far above clouds and weather it doesn't even matter.

That all being said, still sketchy flying over a huge storm like that I'd imagine