Now you may be asking, why did today's increasing chance in showers and thunderstorms suddenly drop to a mere 20% instead? Take a look at the surface observations below. The left (11am EST) is superimposed with the radar, and the right (1PM EST) is superimposed with the surface observations.
So this brings us over to the left picture and the question, why did the chance of showers and storms drop so fast? Take a look at the what the red arrow on the left is pointing at. That's where the large area of high pressure was supposed to be until this afternoon, but instead the upper-level winds pushed it far out into the Atlantic, meaning that the cold front was free to push on through faster.
So there you have it. Keep your umbrellas on hand just in case until the weekend, especially into Sunday Monday and Tuesday as the sunshine will be in full force.
As for now, time to get a slurpee to counteract all this humidity.