The fireworks show is approaching the region as a line of powerful storms advances southeastward on a line from near New York to the Baltimore area.
Check out some of the red-and-yellow in the latest radar image, and the National Weather Service is saying there's a good chance that the storms will hold together.
A severe thunderstorm warning is in effect for parts of Chester and Montgomery Counties, and severe-storm watch is up for everyone else until 9 p.m.
A slow-motion front is colliding with the hot, vapor-laden air entrenched across the reegion, and the results could be dramatic.
A severe-thunderstorm watch means a potential for 58 m.p.h. wind gusts and-or large, damaging hail.
Even if those criteria aren't met, expect some serious downpours into tonight.
Also, the latest forecasts have upped precipitation totals and now call for the potential of an inch-and-half-plus between now and Friday.