More than five inches fell in some suburbs of the capital. The authorities in Maryland rescued dozens of people, including some who were stranded in their cars.

Major I-95 cities -- Philadelphia, Baltimore, Washington, D.C., and Richmond, Virginia -- could be impacted as heavy downpours could bring 2-3 inches of rainfall per hour over already saturated soils, which could easily cause flash flooding.

Flood Watch issued by NWS Baltimore MD/Washington due to excessive rainfall, with potential flash flooding in DC, MD, VA, and WV. Heavy showers expected; weekly forecast includes thunderstorms and high humidity.

"Pine Valley is one of our big concerns with the burn scar from the forest fire," said Washington County Emergency Services Director Jason Whipple. "And that tends to be a problematic area because of the runoff that comes down there and the debris that comes with it.

The Trump administration has changed course and is moving ahead with work to develop a new database that would provide Americans with precise estimates of their flash flood risk in a warming world.

As flash flooding hits the Northeast, here's what to know about the dangerous weather phenomenon.

The catastrophic Texas flash flood along the Guadalupe River is simply heartbreaking. What can be learned and applied here in Western Washington?

Maryland Department of Transportation cameras captured cars on I-495 westbound slowly splashing through the highway.