Looks like we have a broad SW flow at the surface and aloft, so I don't think we're going to have to worry too much about a river wind. But hey, it's DCA.
If the HRRR is to be believed, it's possible that DCA and Cumberland could top into the upper 80s or even get a cheap 90 degree reading. DCA, because it's DCA. Cumberland, because of downsloping.