6:40 p.m. — Storms about to exit region near Annapolis. Severe thunderstorm watch cancelled to the west. Mostly quiet weather for the rest of the evening.
The last of the storms is pushing through eastern Prince George’s and southern and central Anne Arundel County, generally right along Route 50, where a severe thunderstorm warning remains in effect until 7 p.m. Annapolis should get hit just before 7 p.m. This storm, which is producing heavy rain, frequent lightning, and strong winds, should exit east into the Bay between 7:30 and 8 p.m.
To the west of Prince George’s County, the severe thunderstorm watch in effect earlier has been cancelled and just some widely scattered showers are expected through sunset.
See below for the forecast through tomorrow and earlier storm updates.
Detailed forecast through Thursday
It was another hot and humid one — the usual these days! High temperatures rose to near and past 90 yet again, making it the 50th day of the year to go that high. As we think about all these hot days, and we’ve got another one coming, keep in mind that they are on borrowed time.
Through tonight: Storms are less widespread than on Tuesday, but we still run the risk of a few strong ones in the region through sunset or a little beyond. Overnight it will be partly cloudy, perhaps with a few spots of fog. Lows will range from near 70 to the mid-70s. Winds will be light and variable.
View the current weather at The Washington Post.
Tomorrow (Thursday): We have one more day until things really start to change. It’s a lot like today and many days before it. Partial sunshine gives way to an afternoon or evening storm risk, although for now they don’t appear to be a big deal. Highs will range from near 90 into the low 90s in most spots.
Earlier storm updates
6:15 p.m. — Severe thunderstorm warning from College Park to near Annapolis, including Bowie
An intense storm centered over Greenbelt and New Carrollton is sweeping east-southeast at 25 mph. It has intensified in the last 15 minutes, unleashing a 63 mph gust in College Park. In the storm’s path include Bowie, Kettering, and Crofton and it may land around Annapolis close to 7 p.m., when the warning expires. Heavy rain, frequent lightning, and wind gusts to 60 mph or so are possible.
6 p.m. — Storms from northern part of the District into Silver Spring through Laurel, sweeping east
Storms span from the northern part of the District through Silver Spring northeast up Interstate 95 to Laurel. This whole complex is sweeping east toward Greenbelt and Bowie into central Anne Arundel County generally right along and north of Route 50. Some locally heavy rain and lightning are likely with these storms.
4:45 p.m. — Storm organizing around Leesburg into southwest Montgomery County and heading east
Radar shows an area of storms from northern Loudoun County into southwestern Montgomery County. These have some locally heavy rain and perhaps some lightning but are not severe. However, there is a possibility they’ll intensify and grow as they march east. They could move into Washington’s western and northern suburbs between 5:00 and 5:30 p.m. and enter the Beltway between 5:30 and 6 p.m. We’ll keep you posted.
4 p.m. — A severe thunderstorm watch is in effect for the D.C. area and points north until 10 p.m.
The National Weather Service has issued a severe thunderstorm watch for the immediate Washington area and location to the north until 10 p.m. This includes the District of Columbia, as well as Arlington, Fairfax, Loudoun and Prince William counties. Most of Maryland and Delaware is included in the watch.
Storms firing in our far western areas late this afternoon will potentially form a broken line that will march east through the evening. Additional scattered thunderstorms will form ahead of the line.
- Timing: 4 to 6 p.m. west of the Beltway, 5 to 7 p.m. in the District, 6 to 8 p.m. farther east.
- Impact: Gusty winds, frequent cloud-to-ground lightning, potential hail, heavy rainfall.
- Areas affected: Better chances farther north and west and eventually northeast of the District; threat wanes south of Fredericksburg to the Luray line.
Storms will taper off as the sun sets, giving way to isolated showers overnight.
Storm discussion from earlier
There is no single, dominant ingredient this afternoon that is screaming out “Severe storms likely!” — rather, a combination of subtle features that may interact in just the right manner for a few hours. This is likely what motivated the issuance of a severe thunderstorm watch … which is, in essence, a southward extension of an even more ripe watch region to our northeast.
Yes, the atmosphere has destabilized — not to the same degree as yesterday afternoon — but there is enough buoyant energy to support strong storms. An upper air disturbance passing through has increased the winds aloft, thus making the shear (increase in wind speed with altitude) stronger. The locally enhanced shear (25-30 knots) is enough to induce longer lived and more intense storm drafts.
In terms of storm triggering, again … nothing major in play, rather the usual “local” suspects, including forcing by the high terrain to our west. In fact, storms were popping there as of 4 p.m. The high resolution (convection-allowing) models run this afternoon suggest that a line of storms will congeal along the eastern slopes of the Blue Ridge, then sweep through the D.C. region around 6 p.m., as shown below.
What type of hazards do we expect? Briefly torrential downpours and in some spots, very intense lightning. The combination of wind shear and a lot of buoyant energy concentrated in the “hail growth zone” aloft suggests one or more location could size hail stones ranging in size from dimes to quarters. Small pockets of damaging wind (microbursts) reaching 60+ mph are also possible.
With loss of daytime heating, and consumption of residual buoyant energy by existing storms, the activity will wind down fairly quickly by 9-10 p.m.