National Weather Service United States Department of Commerce

Snow in the Great Lakes; Windy Conditions in the East

Lake effect snow will impact the Great Lakes region through the day. Gusty winds will pick up across the Midwest, Northeast and Mid-Atlantic beginning this afternoon following a cold front. Elevated fire weather conditions will persist across the Desert Southwest today, with critical fire weather conditions developing Wednesday and Thursday in the Southern Plains. Read More >

Heavy rain and flash flooding in Washington

Thursday afternoon September 10th 2020

 

Early on Thursday afternoon, showers and thunderstorms arose along a weak atmospheric boundary oriented north to south across the Washington area. The storms that formed were fed by tropical moisture to our southeast which allowed for heavy rainfall rates. In addition, weak winds in the atmosphere kept the storms moving slowly. That combination of heavy rain and slow movement allowed for 2-5" of rain to fall in a relatively narrow corridor across parts of the Washington metro area. Most of that rain fell within 2 hours.

The heavy rains produced flash flooding of numerous roads and streams and first responders conducted several water rescues. The hardest hit areas were: the District of Columbia, Arlington and Alexandria Virginia, and the Maryland suburbs in Prince Georges and Montgomery Counties.

 

Listing of rain totals: linked here.

Listing of reports of flooding & flash flooding (received by NWS Baltimore/Washington): linked here.


Map of radar estimated rainfall: (Areas in red are 3"+)

 

Radar Loop showing the storms from 1:25 - 1:49 P.M.

Radar loop

 

Satellite Image at 2:30 P.M.

Satellite image

 

Link to images of flooding: (using internet search "DC flooding September 2020")