This afternoon’s models have backed off on the extreme weather just a bit.  Most of the severe activity will move in between 8-12 midnight.  Accumulated precipitation values have come down a bit to 1-2 inches of rain with additional rain on Thursday afternoon and evening.

Shear, Helicity and Vertical Velocity values have reduced a bit from yesterday’s posted graphics with the heaviest activity now predicted to occur in the northern suburbs of Philadelphia, Berks, Lehigh and Bucks counties and into central/ northern NJ and New York City.

HRRR Model Maximum Upward Vertical Velocity 9 PM (black shading)

That said, these locations are hard [impossible] to pin down precisely in advance.  There are differences in the models.

It’s a good thing I don’t usually “do thunderstorm forecasts”.  This would have to become a full-time job!