Since the 1996 disaster, when eight climbers died in a sudden storm, forecasting on Everest has become serious business. "Prior to that accident, people were not getting forecasts," says Michael Fagin, president and lead forecaster of West Coast Weather, a custom forecasting service. "Getting communications to Base Camp was pretty crude in the late nineties," he explains. Today, Fagin is the weatherman in chief for most major expeditions each spring. For several weeks before the summit push in late May, he keeps in close contact with team leaders at Base Camp from his office in Washington State, where he analyzes data and satellite images from at least six U.S. and international models. "I'm not always just saying, 'The winds are going to be x.' Sometimes I'll say, 'Boy, given this type of pattern, I have a low confidence in what's going on.' " Fagin's perfect summit window means light winds, with the jet stream migrating north and the monsoon well south of Everest. Minimal precipitation is ideal, but "forecasting that gets tricky anywhere," he says.