Heavy rains are being predicted for the entire region the next two days, and emergency agencies are warning that may mean flash flooding.
A flash-flood watch has been issued for the area, to be in effect Friday afternoon through Saturday afternoon. According to the National Weather Service, a stationary low pressure cell may bring torrential rains.
Low pressure is going to develop over the Mid-Atlantic Friday and remain nearly stationary this weekend. This will have the potential to bring 3 inches or more of rain to the region through Saturday afternoon. Thunderstorms could cause locally higher rainfall amounts.
Heavy rainfall may result in rapid rises in streams and creeks. This could quickly result in flooding… especially in low lying and poor drainage areas.
Precautionary/preparedness actions… a flash flood watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation. You should monitor later forecasts and be prepared to take action should flash flood warnings be issued.
WEATHER UPDATE: Flash Flood Watch issued for DC and region Fri PM- Sat PM. 3" or more rain possible by Saturday night! pic.twitter.com/x8LHzY7upF
— Tucker Barnes (@TuckerFox5) July 27, 2017
The Washington Post’s Capital Weather Gang says this storm’s structure is similar to that of a winter storm. They say some pockets within the storm may see upward of 7 inches of rain.
“Heavy storms may line up along a corridor and hit the same areas repeatedly — a worrisome phenomenon known as training,” the CWG says. “Areas that experience training will be most prone to flooding.”
Fairfax County offers some of the following tips of how to stay safe if flash flooding occurs or has the potential to occur:
- Move immediately to higher ground. Do not wait for instructions to move.
- Always stay away from floodwaters.
- If you must walk in water, walk where water is not moving; use a stick to check the ground.
- Be aware of streams, drainage channels and other areas known to flood suddenly. Flash floods can occur in these areas with or without such typical warnings as rain clouds or heavy rain.
- Keep your children inside and away from streams and creeks.
- Stay away from downed power lines to avoid the risk of electric shock or electrocution.
- Keep your vehicle parked in your garage or on the driveway away from low-lying areas and large drains.
Residents are also reminded not to drive on flooded roads:
- Stop and take an alternate route. The depth, current and condition of the road are all unknowns and can be deadly.
- If your vehicle stalls on a flooded road and water is rising, get out of the car, call 9-1-1 and move to higher ground.
- Be especially cautious during periods of limited visibility or nighttime when it is extremely difficult to see and judge conditions — state law requires headlights when wipers are on.