The problem is that this is a small low and the moisture availability is modest at best. PWATs don’t even get close to 1”.
Part of the reason why this looked like a region-wide soaker from several days back was that the two parts (wave then low) nicely hit different areas. The wave part ended up being a dud for most of us except for up by Hagerstown. I got a trace.
18z NAMs and HRRR look fine. Most of us over an inch, and up to 2"+ in lucky spots. The difference is that the HRRR centers the precip in the center and east of the DC/Balt region, while the NAMs favor spots W of 95.