It can be a tough summer to fly. According to the Transportation Security Administration, more passengers than ever will be flying. And the weather so far this year hasn’t really cooperated. A blizzard warning in San Diego, sudden turbulence that injured 36 people on a Hawaiian Airlines flight to Honolulu, a 25-inch downpour of rain that swamped an airport in Fort Lauderdale, Fla. Skies baffled forecasters and frustrated travellers. And it can only get worse as the climate continues to change. Intense events are happening more often and outside of their seasonal norms, said Sheri Bachstein, chief executive of the Weather Company, part of IBM, which makes weather forecasting technology.…