The National Weather Service incorrectly forecast 30 inches of snow for New York because they used the wrong forecasting model. The impact and path of the blizzard was forecast based on a European model, rather than their own system, which had actually been upgraded in recent weeks. “Too much trust was based on a single model, and there was not enough emphasis on uncertainty,” said Jeff Masters, chief meteorologist at Weather Underground. “The European model was about 100 miles off. That is a big deal for a heavy snow situation.” The National Weather Service's Global Forecast System actually did correctly predict the blizzard's worst would not hit New York City.