The D.C. region has already had what is usually a month's worth of rain—and June isn't even half over. Yet the time of the year might explain why we've been spared severe flooding so far.
It's technically still spring, and most of the area's vegetation is young and growing. To keep doing that, plants need water—and there's been plenty of it this month. Wendy McPherson, a hydrologist with the U.S. Geological Survey in Baltimore, says thirsty flora have kept ground water levels well beneath flood stage.
"I looked at the well near Baltimore and that's come up a half a foot. That's not a lot. And that indicates to me that a lot of this is getting soaked up by the plants, trees and grass, drinking this up before it gets down to the water table," she says.
The threat of flooding still remains—a flash flood watch is in effect through Thursday evening—but McPherson expects any from this storm will be localized in small streams and creeks. She says the water levels in the Potomac River in and around D.C. should be able to handle another big rain storm.