As outlined in Bastardi's preliminary seasonal outlook-the full 2006-2007 AccuWeather.com Winter Forecast will be released in mid-October-the winter in the Northeast and Midwest is expected to begin mild before turning significantly colder in January and February as cold air pours down from Canada. Overall, New York City and Boston are expected to average slightly below normal for the three-month winter period of December through February. The winter along the East Coast and Gulf Coast will be marked by stormy weather, because of the pattern created by the El Niño that formed this summer and was identified by Bastardi in the late spring.
El Niño and the East Coast Winter
An El Niño-a cyclical warming of Pacific Ocean waters-directs strong wind currents that tend to hinder hurricane development in the Atlantic Basin during the summer, and lead to a more active southern jet stream in the winter, which creates a wetter-than-normal pattern for the South and Southeast U.S. This precipitation works its way up the East Coast, bringing more storms to the region. "While the East Coast will most likely experience more precipitation, it is too early to tell whether the majority of this precipitation will be in the form of rain or snow," said Bastardi. "Timing will be the key in the major cities of the East Coast. Cold air from the north arriving too early or too late would lead to more rain and less snow."
Added Bastardi, "Given the overall pattern and the water temperature profile we expect, the region will likely see one or two major Nor'easters."