The focus today and Wednesday will be the potential for severe weather across the Northeast. A cold front will blast across the area and aloft, a very strong jet streak will plunge in helping to increase the upward motion and potential for severe storms including supercells with large hail and damaging winds. Dew points, while low today, will rise into the 60s ahead of the front and the shear will also increase helping to support rotating storms.
An initial round of thunderstorms will occur in the morning but should move out allowing for heating during the afternoon. Storms will develop after 3:00 pm EDT from western New York into West Virginia and strengthen moving East.
I outlined an area across northern Pennsylvania and New York where the shear is the greatest resulting in the greatest risk for a tornado. I think the Wednesday morning soundings and simulated radars will help to identify areas where tornadoes may occur.