While the entire Northeast can expect a few thunderstorms today, some parts will be on the lookout for some more severe, scattered thunderstorms. As a cold front makes its way across the northern Ohio River Valley, it brings with it the risk for severe, possibly tornado-producing storms.
Beginning this afternoon, scattered severe thunderstorms will be possible from Ohio to southern New York and northern New Jersey into tonight. A low pressure system at the surface will make its way offshore from the Great Lakes throughout today. Its associated cold front is expected to trail underneath, swinging across the northern Ohio River Valley and over southern NY and NJ. As daytime heating warms the surface today, air will lift and storms will be able to develop as early as this afternoon.
Storms will be most severe and have the greatest potential for tornado formation in northern PA and possibly northwest NJ. As the jet dips right over northern PA late this afternoon, the leading edge of this streak will enhance lifting and increase the possibility for more severe weather in this area. Combined with low-level shear, relatively low LCL heights, and plumes of moderate CAPE in northern PA, the risk for tornado development is enhanced.
In addition to possible tornado development, strong winds and hail are also possible, mainly over northeastern OH, northern PA, and northwestern NJ. These factors, as well as heavy rain and localized flooding, can also be damaging and dangerous.
These storms are expected to diminish tonight as the cold front moves offshore and instability diminishes. Despite the passage of a cold front, cooler temperatures are not expected to last south of NY as a high pressure ridge continues to dominate in the southeast.