Well, that wasn't the point exactly. Your post was wrt the 18z NAM precip distribution. The reality is as the tropical remnants move NW and interact with a front/encounter the cool/dry HP pushing in from Canada, there will probably be more than one associated disturbance impacting the region. The actual remnant low may result in a precip max to the SW of the DCA-BWI corridor, and then as the flow shunts everything eastward, there looks to be a developing coastal low resulting in heavy rains along the coast later in the weekend/early next week, thus another precip max to the east.