I was waiting for my pax one day in Oklahoma flying a Falcon 20 as captain. Reports were a storm was approaching the airport with hail and a tornado warning. I had the plane put in a hangar until it passed and told my pax we had to wait until it passed. I watched the last take off, a twin engine Cessna take off with a 10 knot headwind. As he passed the end of the runway the wind switched to a 40 knot tailwind with heavy rain. He was very lucky. If we had taken off behind him we would not have made it. As SSR said don't count on luck with wind shear. It might not be your lucky day.