As the frontal boundary that will bring an end to this pattern oozes southeast tomorrow, the potential for more soaking showers and storms will continue across the region. Modeling has been rather inconsistent in identifying specifics regarding the thunder over the past few days -- each run shows a different possibility but the general trend that any storm that impacts the region *can* produce heavy rain has been accurate...and that trend will continue to hold serve into Friday.
With the front closing in on the Delaware Valley, more scattered thunderstorms are in the offing for tomorrow...some of which show the potential for heavy rains. The Euro below shows that some spots could pick up a quick half inch or more of rain tomorrow morning with thunderstorm activity in the area. Other models are a bit less generous, the GFS a bit more generous tomorrow afternoon.
To show that scattered nature of thunderstorm activity -- here is this morning's high res version of the NAM showing the potential rainfall distribution through Friday evening. Some spots are high and dry -- others pick up an inch to three inches of rain. Even on the high res, the placement of these heavy rain bands has varied from run to run so determining where exactly the "winners" are in the heavy thunderstorm activity will amount mostly to a nowcast...the operational modeling out there suggests areas north and west of the city, the high res isn't necessarily in agreement on that.
PWAT's (our little index of moisture in the atmosphere) peaks out at 2.3 tomorrow afternoon. While the higher PWAT's didn't yield much in the way of heavier rain so far...the potential still does exist and we have to note it since the atmosphere is as chalked full of moisture as it is.
Just know that the potential for some locations to get a soaking of rainfall is in the cards tomorrow and tomorrow evening.