October 29th and 30th, 2021 - 2021 Record-breaking Coastal Flooding Along the Potomac River and Chesapeake Bay

On Tuesday, October 26th, 2021, a low pressure system was located over the Ohio Valley region, which produced winds that blew into the Chesapeake Bay and tidal Potomac River from the Atlantic Ocean. This was followed by a similar system rising out of the Mississippi River Valley region on Friday, October 29th, 2021. This led to a prolonged period of onshore winds and one of the worst coastal flooding events in recent history.

The highest water levels from the event were measured along the tidal Potomac River near the Georgetown area in Washington, D.C. Friday afternoon, the water levels in this area was measured at 8.19 feet. Although this was not a record high water level for the location, a few other nearby areas did experience record high coastal flood waters. A water level measuring gauge in Dahlgren, Virginia set a record for highest recorded water level in the area late Friday morning, measuring in at 5.64 feet. Friday evening, the measuring gauge at Straits Point, Maryland also recorded a record high water level, at 4.90 feet. Around this same time, water levels also peaked at the measuring gauge in Solomons Island, Maryland along the Chesapeake Bay, reading 4.82 feet. 

​...Forecaster Zach...