Models suggest the heaviest rain in the D.C. region will fall around 4-7 a.m. west of I-95 and 7-10 a.m. east of I-95. Some embedded thunder and a strong wind gust or two (up to 30-40 mph) cannot be ruled out as this all comes through.
Rainfall totals are likely to be about 0.5-1.0 inches which may cause some ponding of water on the roads and low visibility for a time, but widespread flooding is not expected.
The bulk of the rain may be over by midday Thursday, although it’s not out of the question that a narrow line of showers – maybe with a bit of thunder – zips through later during the afternoon when the actual cold front passes. But don’t be surprised if we see a good deal of sunshine in the afternoon with temperatures surging well into the 60s before the cooler air arrives Thursday night into Friday.
Below, find model rainfall forecasts. Note they are pretty consistent in simulating 0.5-1.0 inches.
NAM model: 0.6-0.9 inches
High resolution NAM model: 0.3-1.0 inches
GFS model: 0.8-1.0 inches
European model: 0.4-1.0 inches