Rain Update
The rain here has pretty much stopped except for a little sprinkle now and then. As of 9 pm, National Airport had recorded 7.34 inches over the past two days. I believe this one storm exceeded the normal October rainfall. The highest reported rainfall I have seen so far has been Montebello, VA, which recorded 11.36 inches.
The rain was badly needed, but some areas may take some time to recover from such a heavy amount in such a short period. So far I have heard about flooding, power outages, and delays on trains leaving Union Station where a tree fell on the wiring for a train signal. An evangelical gathering on the Mall also got washed out.
If I lived along anyway of the streams like Rock Creek or the upper Anacostia River, I would be very worried about flooding tonight as the runoff makes its way down the tributaries. Roadways and bridges along these waterways have also been known to wash out from time to time, and after a rain like this, they will be especially dangerous.
Update (Sunday morning): Capital Weather has a graph of the rainfall recorded at National Airport over the last two days. According to this article at least, we may now have a colorful fall instead of a crispy brown when the leaves turn.