Flood watch: Thunderstorms, heavy rain expected Friday evening

The National Weather Service (NWS) has issued a flood watch for central and southeastern Montgomery County from Friday evening until early Saturday morning due to expected heavy rainfall that may cause flash flooding.

According to a weather service alert, showers and thunderstorms will begin late Friday afternoon into the evening with rainfall of about 1 to 3 inches within an hour or two.

“Storms may also train over the same areas, causing the possibility for locally higher amounts around 4 to 5 inches of rain within a few hours,” the NWS alert said. “Heavy rainfall in a short period of time combining with already saturated soils means that creeks and streams may rapidly rise out of their banks along with the potential for flash flooding in urban areas.”

According to the weather service, the heavy rainfall may cause runoff, flooding of rivers, creeks, streams and low-lying locations.

Those who may be driving should turn around and avoid flooded roadways and never drive around barriers blocking a flooded road, according to NWS.

“The road may have collapsed under that water,” NWS’s flood safety website states. “A mere 6 inches of fast-moving flood water can knock over an adult. It takes just 12 inches of rushing water to carry away most cars and just 2 feet of rushing water can carry away SUVs and trucks.”

Area residents are encouraged to monitor forecasts later in the day and visit www.weather.gov/safety/flood for flood safety and preparedness information.

A flood watch is issued when conditions are favorable for flooding to occur, but it does not mean it will occur, just that it is possible, according to the NWS. A flood warning is issued when a hazardous weather event is imminent or occurring.

The flood watch is in effect for Prince George’s, Charles and St. Mary’s counties in Maryland; Arlington, Falls Church and Alexandria in Virginia; and Washington D.C.