Heavy rain, flooding likely as fast-moving Isaias expected in DC area Tuesday

If you have outdoor plans in the 24 hour period beginning Monday night, the chances are good you may wind up inside.

Tropical Storm Isaias should begin to make its presence felt south of the District on Monday night, and substantial rain, up to 6 inches to the east of the city, is expected Tuesday.

The National Weather Service issued a tropical storm watch for much of the region, and areas east of Interstate 95 are under a flash flood watch starting Monday night. The storm’s highest wind speeds, according to Storm Team4’s Somara Theodore, should be felt on the Eastern Shore beaches.

She notes, though, that the storm should not linger.

“As quickly as it arrives, it also moves out,” she wrote in an email.

The weather service said the biggest impact to the D.C. area will likely be the flooding that the storm brings on Monday evening and into Tuesday. It said coastal flooding could also be severe.

Due to Tropical Storm Isaias’ threat to our area, a Tropical Storm Watch has been issued for counties along the I-95 corridor and east. Flash Flooding will likely be our biggest impact Mon eve — Tue eve. Tidal/coastal flooding (Tue and Tue eve) is also a concern. Stay informed. pic.twitter.com/ClQOF1a9Oi

— NWS Baltimore-Washington (@NWS_BaltWash) August 2, 2020

Even though the storm weakened from a hurricane on Saturday, Isaias — currently near Florida — is forecast to parallel the U.S. East Coast, according to Storm Team4 meteorologist Lauryn Ricketts, a path which would bring tropical storm conditions to the region from Monday night through Tuesday.

The storm — pronounced ees-ah-EE-ahs — had already prompted Virginia Gov. Ralph Northam to declare a state of emergency for the potential of heavy rain and gusty winds from coastal Virginia through Maryland’s Eastern Shore.

Listen: How to pronounce the name Isaias

While Isaias’ path is still uncertain, it appears increasingly likely that eastern Virginia could be impacted and must prepare for the possibility of flooding, high winds and potential storm surge, a news release from Northam’s office said.

The National Hurricane Center’s official forecast track as of Sunday morning had Isaias making landfall as a strong tropical storm in the Carolinas late Monday, before racing northward over the Chesapeake Bay through New Jersey with sustained winds between 45 and 60 mph.

“Confidence for the heavy rainfall is highest along and east of the Blue Ridge Mountains, but the area may shift depending on the exact track of Isaias,” the National Weather Service’s D.C. regional office said in its Sunday forecast discussion.

“The best chance for tropical storm force winds will be near and east of the center of Isaias, but the heavy rainfall may extend well north and west from the track of Isaias.”

D.C. Mayor Muriel Bowser asked residents Friday to prepare for the possibility of heavy rain and high winds. One of the region’s power companies asked residents to prepare an emergency kit that also included items like hand sanitizer and face masks due to the pandemic.

Bowser said in a news release that the D.C. Homeland Security and Emergency Management Agency had begun emergency planning with its local, regional and federal partners; and more information will be provided as the hurricane’s trajectory becomes more precise.

The Virginia Hurricane Evacuation Guide During the COVID-19 Pandemic outlines preparedness, response and recovery actions, and Northam urged Virginians in coastal areas who may be affected to consult it in making preparations.

For more on hurricane preparation, visit the FEMA website. Find more tips on the Ready DC website and the Virginia Department of Emergency Management.

WTOP’s Alejandro Alvarez and The Associated Press contributed to this report.

Forecast:

Monday: Increasing clouds and muggy, with rain starting during midday, getting heavier south of the District in the evening. Highs in the mid to upper 80s.

Tuesday: Tropical Storm Isaias arrives in the area, making its presence known with rain, steady at times. Flooding likely in coastal areas. Highs in the upper 70s.

Wednesday: Mostly sunny and less humid as Isaias moves north. Highs in the mid 80s.

Thursday: Mostly sunny. Highs in the mid 80s.

Current conditions:

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