According to the National Weather Service’s Weather Prediction Center (WPC), a flash flood threat persists across the Mid Atlantic today and will continue into tomorrow.
Broad mid-level ridging centered off the Carolinas will continue to extend back to the west as far as the Southern Plains. This will persist the moist and unstable environment that has been plaguing much of the east for several days now, resulting in another day of scattered to numerous thunderstorms. Today, the focus for convection will likely be along the decaying front which will drag slowly southeast as it wanes, reaching from the Ozarks to the Mid-Atlantic states, although with some oscillation north-south expected at times.
According to the WPC, along this boundary, a generally southwest flow emerging from the Southern Plains will drive periodic impulses northeast, interacting with the front and providing locally enhanced focused ascent for convection.
The atmosphere is ripe with an overabundance of moisture, allowing any shower or storm that pops up to drop 2″ or more of rain per hour.
The WPC says that conditions should create widely scattered showers and not a widespread heavy rain event across a broad area. However, any showers or storms that do pop up can dump extremely heavy rain, especially in the area stretching from the Central Appalachians into the Mid Atlantic coast.
More of the same is expected tomorrow with Pennsylvania being the bullseye for the greatest chances of excessive rainfall.
