NoVA, DC Weather: Double Whammy Of Record Heat, Severe Thunderstorms

VIRGINIA/DC — Residents in nine Virginia counties, and six cities, are under a severe thunderstorm watch Thursday afternoon and evening, the National Weather Service said. The storms may produce damaging winds and rain.

The watch is in effect until 11 p.m. for Arlington, Clarke, Fairfax, Fauquier, Frederick, Loudoun, Prince William, Shenandoah and Warrent counties, plus the cities of Alexandria, Fairfax, Falls Church, Manassas, Manassas Park and Winchester.

An excessive heat warning will be in effect from 11 a.m. to 8 p.m. Friday for the DC region. The warning means dangerously hot conditions with a heat index value — or "feels like" temperature — around 110 degrees is expected in the District and Northern Virginia, the National Weather Service said.

It’s not just excessively hot temperatures — it will feel like 104 degrees outside — Northern Virginia and D.C. residents will need to deal with on Thursday. The National Weather Service also is calling for scattered thunderstorms, some with damaging winds, for the afternoon and evening.

A heat advisory is in effect for the entire Washington, D.C. area from 11 a.m. to 8 p.m., while the best chance for severe storms will be between 4 p.m. and 10 p.m. on Thursday, according to the NWS.

As the day progresses, a gusty southwest wind will make it “feel more like a blast furnace than giving much relief,” the Washington Post’s Capital Weather Gang reported.

With temperatures possibly touching 100 degrees, scattered storms are likely to pop up to the west in the afternoon, creating a threat of locally damaging winds and heavy downpours as they head east into the closer-in suburbs and D.C., according to the Capital Weather Gang.

"Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities," the NWS said.

While the heat index is forecast to be worse on Friday due to higher humidity, thunderstorms are expected to be less numerous than on Thursday. Forecasters are saying D.C. could once again challenge the calendar-day record on Friday, which is 100 degrees.

Thursday will be hot and will come with a slightly better chance of a storm, while Friday is expected to be the worst, with the heat index close to 100 degrees, NBC4 reported.

"As temperatures make a run at 100 degrees Fahrenheit in Baltimore and the upper 90s in Washington, D.C., New York City and Philadelphia are among the major metro areas where temperatures will peak at or above the 90-degree mark for three days in a row — the official designation for a heat wave in the Northeast," AccuWeather reported Thursday morning.

Fairfax County has activated its heat plan for both Thursday and Friday. Cooling centers across the county will be available during normal operating hours for people needing relief from the heat. The centers will also have supplies available, including bottled water, sunscreen, insect repellant, and body wipes.

Arlington County is offering shelters and resources during the heat wave. Financial assistance with air conditioning repairs are available by calling 703-228-1350. Alexandria residents without access to cooling in their homes or a place to cool off can find various options around the city. Cooling centers are designated at recreation centers and library branches.

The District of Columbia has activated its hot weather emergency plan now through Sunday.

Here is a look at the National Weather Service forecast through the upcoming weekend for Northern Virginia and D.C.:

Thursday: Scattered showers and thunderstorms after 4 p.m. Mostly sunny and hot, with a high near 98. Heat index values as high as 105. Southwest winds 10 to 14 mph, with gusts as high as 24 mph.

Thursday night: Showers and thunderstorms likely, mainly before midnight. Some of the storms could produce gusty winds. Mostly cloudy, with a low around 75. Southwest wind 5 to 11 mph, with gusts as high as 20 mph.

Friday: A chance of showers and thunderstorms after 3 p.m. Mostly sunny and hot, with a high near 98. Heat index values as high as 109.

Friday night: A chance of showers and thunderstorms, mainly before 9 p.m. Partly cloudy, with a low around 76.

Saturday: A chance of showers and thunderstorms, mainly after 3 p.m. Mostly sunny and hot, with a high near 97. Southwest wind 6 to 11 mph, with gusts as high as 18 mph.

Saturday night: Showers and thunderstorms likely between 9 p.m. and 3 a.m., then a slight chance of showers. Mostly cloudy, with a low around 73.

Sunday: A chance of showers after 9 a.m. Mostly sunny, with a high near 86.

Sunday night: A chance of showers before 9 p.m. Mostly clear, with a low around 67.