As mentioned in past posts this week, two areas of low pressure will combine Thursday night to form a significant coastal storm off the Delmarva coast Friday.  This storm  will intensify and become somewhat fixed in position as blocking high pressure in the Atlantic prevents its usual movement away.

While the temperatures during Thursday and Thursday night will be well above freezing, intensification and heavy precipitation rates  during the morning on Friday (QPF values over 0.75 inches in 6 hours) will cause dynamic cooling.

The NAM shows rain changing over to wet snow in Philadelphia sometime during the morning hours Friday and earlier north and west of the city. 

While warm ground surface temperatures and spring-like solar insolation effects (radiant energy through the clouds)  will seriously reduce  the chance of accumulations, it will look quite stormy out with windy conditions adding to the mix on Friday.

Some surface accumulations possible especially on grassy surfaces, if the precipitation continues into the evening Friday.

An interesting and unusual weather system setup!   Expect changes to this forecast.