An incoming cold front that will push through much of the northeastern US today and into tonight will be responsible for the development of scattered thunderstorms, some of which that will likely turn strong to severe. While some of the ingredients are present for the formation of intense storms, other factors will be lacking, thankfully preventing an outbreak of severe weather from occurring.
35 to 40 knots of wind shear, or strong winds aloft will allow for these storms to rapidly form, and some to even grow tall enough to bring down these upper-level winds to the surface. There will also be plenty of heat present in addition to the moderate moisture and instability, making for another favorable component of this thunderstorm setup.
During the early-afternoon hours, a line of scattered thunderstorms will be moving southeastward across Upstate New York through interior sections of northern New England. Storms will be more scattered toward the Ohio River Valley thanks to the weaker wind shear in place. As the cold front gradually progresses to the south, so will the storms as they move into central New England and coastal Maine by the evening. By this time period, however, the storms will become more isolated, especially in the northern Mid-Atlantic. There is the concern for the development of a couple supercell thunderstorms by the evening hours in northern New England, thus enhancing the risk for damaging winds and large hail.
As we get into the overnight hours, the storms should fizzle in the Mid-Atlantic while they slow down across central New England. Localized flash flooding will be possible while the severe weather threat winds down. The southern coast of New England should remain dry while showers clear out at around sunrise in southeastern New England and the Maine coastline.