With summer comes thunderstorms

Summer weather arrived today as the pesky ocean storm that was holding clouds and cold temperatures over the region has finally moved away. Low level moisture is very well established, with dew points in the 60's across the region. High temperatures have reached the low 80's over western New England and a few 90's have shown up southwest across Pennsylvania. All in all, this spells instability. CAPE has reached 1500 to 2000J/kg further west this afternoon. Low pressure entering Quebec is dragging a cold front across the eastern Great Lakes. A prefrontal trough is already the focus for a solid complex of severe storms over western New York with single cell storms popping up further east. These will tend to wane in strength with the loss of daytime heating, however there is still the chance for a shower and/or some thunder later tonight around midnight to 1am.

We will see an increase in clouds Friday morning as the cold front approaches the region. The timing of the front will largely dictate the severity of storms that develop. An early passage will result in limited time for destabilization, and vice versa. We will see an increase coverage of thunderstorms toward the early afternoon, with showers and storms becoming likely over western New England by 1pm, spreading to eastern areas by 4pm.

Winds will be unidirectional west-southwest with height with about 30kts of speed shear. This will support primarily damaging wind potential, although small hail cannot be ruled out further west, closer to the mid level cold pool.

The severe threat should end over western New England by 6pm, eastern zones 9pm.