Significant Tidal Flooding Expected By Forecasters In Alexandria, DC

ALEXANDRIA, VA — Significant tidal flooding is expected in coastal areas of the DC area Friday and Saturday, according to the National Weather Service's Baltimore-Washington office.

NWS forecasters say the tidal flooding could potentially be the most significant since Hurricane Isabel in some locations in 2003. Areas at risk include Alexandria, Washington, DC, Annapolis, Bowley's Quarters, and St. George Island.

Forecasters say tidal levels are already elevated, but the highest tides are expected Friday daytime through Saturday morning. Potential impacts of tidal flooding could include impassable roads, water in low-lying area buildings, and flooded docks and marinas.

Free sandbags will be available for City of Alexandria residents and businesses Friday, Oct. 29, from 7 a.m. to 9 a.m. at 133 S. Quaker Lane. These will be first come, first served with a limit of five sandbags per address. Proof of residency or business in Alexandria is required. Residents should wear a mask and review guidance for proper use of sandbags.

A coastal flood warning is in effect until 8 a.m. Sunday, especially around high tide for coastal areas of Arlington County, City of Alexandria and District of Columbia. Coastal areas of Fairfax County, Manassas, Manassas Park, Prince William County and Stafford County are under the warning until 8 a.m. Saturday.

Forecasters expect much of DC's East Potomac Park, part of Navy Yard and near the Joint Base Anacostia-Bolling marina will flood. In Alexandria, floodwaters could go a block and a half inland on King Street. On Friday, Alexandria Police reported Union Street is closed between Queen Street and Prince Street.

Tidal flooding has already impacted lower King Street overnight. At 2:12 a.m., the highest observed tide in the Potomac River at Alexandria was 4.58 feet. The flood stage is considered to be 3.3 feet, while a moderate flood stage is 4.2 feet and major flood stage is 6.6 feet.

The next high tides are 3:32 p.m. Friday and 3:42 a.m. Saturday. Around 3 p.m. Friday, the high tide is expected to reach 5.25 feet. The highest forecast will be 5.41 feet around 2 a.m. Saturday. The next high tide around 4 p.m. is estimated to be 4.49 feet.

A flood watch is also in effect Friday morning through the afternoon for Alexandria, District of Columbia, Prince William, Manassas, Manassas Park, Fairfax, Arlington and Falls Church. Rainfall between 1 to 2 inches is likely with isolated amounts between 2 to 4 inches possible.

The highest tidal levels recorded in the Potomac River at Alexandria were 8.66 feet on Sept. 19, 2003, when Hurricane Isabel impacted the area. The next highest were 7.4 feet on March 19, 1936, 5.06 feet on April 16, 2011, 5.04 feet on Sept. 10, 2018 and 4.92 feet on April 30, 2014.

Alexandria residents can see tips from the city to prepare for flooding at www.alexandriava.gov/Flooding.