A strong Nor’easter is expected to develop from a center of low pressure that will move from the Midwest over the Mid Atlantic coast Thursday night. Strong winds and heavy precipitation will likely create power outages and hazardous travel on Friday.
While it is certain that a Nor’easter will strengthen rapidly over the Mid Atlantic coast, the type of precipitation received in the NYC Metropolitan Area will depend on its proximity to the coast. As of this afternoon, the ECMWF (European) and the NAM (North American) computer models are forecasting enough cold air to transition the heavy precipitation into snow by 10 am or noon Friday. Snow totals in locations where the precipitation does change over to snow could see snow totals exceeding half a foot to over a foot of snow by Saturday morning.
Over the next several hours, more lines of potentially severe thunderstorms are expected to line up across portions of the Upper Midwest, bringing hail, strong winds, and some isolated tornadoes. As of 2:30 CDT, lines of heavy rain and thunderstorms are developing over portions of Southern Iowa, and are expected to make their way east into Illinois, parts of Wisconsin, and parts of Minnesota. The Storm Prediction Center (SPC), has most of Western Illinois under an ‘enhanced risk’, meaning that the potential for multiple severe storms does exist, and that the threat of tornadoes is elevated as well.