..Mid-Atlantic into southern New England...
As the upper trough amplifies and the surface cyclone deepens over the northern Appalachians, low-level convergence along the attendant surface trough will increase into the morning hours, resulting in the development of low-topped convection that will quickly evolve into a squall line across western NY/PA. The northward advection of mid 60s F surface dewpoints beneath 6 C/km mid-level lapse rates will result in 500 J/kg MLCAPE on a widespread basis ahead of the line, with locally higher values approaching 1000 J/kg in spots.
Some guidance members suggest that surface airmass recovery may be brief ahead of the squall line given the potential for widespread antecedent cloud cover. Still, strong tropospheric wind fields will accompany the squall line, with forecast soundings showing 50+ kt flow as low as 800-700 mb, with 35-40 kt flow contained within the boundary layer, just above the surface.
Regardless of the degree of destabilization that precedes the squall line, downward momentum transport of the stronger flow aloft within the squall line should support strong to occasionally severe surface gusts, mostly in the 35-55 kt range. Scattered instances of tree/wire damage are expected, starting from around western PA during the late morning hours, to the East Coast around early evening.