**Severe thunderstorm watch for southern and southeastern areas until 11 p.m.**

9:15 p.m. update: The severe thunderstorm warning for our eastern suburbs has expired as the worst of the storms push towards the Bay. They still have to push southeastward through Southern Maryland and Stafford County in Va., where they will produce heavy rain and lightning over the next couple of hours.

The storms that came through earlier were quite intense, producing torrential rain that caused flash flooding in parts of downtown Washington with poor drainage (see photos at the bottom of this post) and pockets of damaging winds inside the Beltway.


Map shows areas where trees came down (tree icon) and flash flooding (water icon) was reported. (IEMbot)

This is our latest update for the evening. Read below for the forecast for the rest of tonight and Sunday. For night sky watchers, with clearing skies, you might be able to catch a Perseid meteor shower – so be sure to make a wish!

Forecast through tomorrow:

A strong cold front will swing through the region tonight, spawning thunderstorms out ahead of the boundary. The best environment for severe weather lies north of the Mason Dixon line, but that certainly doesn’t exclude our area from the chance at some strong storms as we are under a severe thunderstorm watch until 11 tonight.

Through Tonight: Front approaches before sunset with a line a storms affecting western parts of our area by 6 p.m. I am thinking that the 6 to 9 p.m. time frame will be the prime time for storms. Heavy rain, lightning and gusty winds will be the main hazards, with some of the storm cells potentially reaching the severe threshold for a time. All storms should be clear of the area by 10 p.m., with clearing happening slowly overnight. Temperatures will settle in the mid- to upper-60s with dew points falling off by morning.

View the current weather at The Washington Post.


A lone paddler on the Potomac River as clouds block the sunlight July 31 in the District. (Ricky Carioti/The Washington Post)

Tomorrow (Sunday): Excellent weather to finish the weekend. Mostly sunny skies, warm temperatures and low humidity. Afternoon highs will reach the mid-80s under a light northeast wind at 5 to 10 mph. Dew points not expected to rise above the mid-60s, so there will be comfortable conditions as far as August goes around these parts. Scattered clouds tomorrow night with lows in the mid- to upper-60s.

See Ian Livingston’s forecast through the weekend. And if you haven’t already, join us on Facebook and follow us on Twitter and Instagram. For related traffic news, check out Dr. Gridlock.

Invest 99 is back: Well, it never really went away, but the piece of energy that the NHC has been monitoring for more than a week is poised to become tropical once again. However, those hoping for a brush with what will likely become tropical storm Gert will have to wait. Model guidance is in good agreement, keeping the system well offshore and away from the East Coast.

Want our 5 a.m. forecast delivered to your email inbox? Subscribe here.

Expired storm updates:

8:52 p.m. update: Here’s a remarkable image of flooding at RFK stadium, where the D.C. United game has been delayed (update, 9:15 p.m.: the game was called off):

8:48 p.m. update:  Storms now stretch from around Manassas to Dale City to Waldorf to Annapolis, having exited the Beltway. They’ve weakened slightly but still may produce isolated pockets of damaging winds, in addition to very heavy rain and lightning. A severe thunderstorm warning remains in effect in Washington’s eastern suburbs until 9:15 p.m.

These storms still have to yet to enter Va.’s Stafford County and Southern Maryland, but are headed in that direction. They probably will weaken some more as they push farther southeast.

8:32 p.m. update: While the heaviest rain has passed through the District, the storm flooded quite a few roads. DC Fire and Emergency Management just shared video of a high water rescue on the 600 block of Rhode Island Ave.:

Our weather station on the roof of the Washington Post (1301 K St. NW) picked up 0.78 inches of rain in just ten minutes, and one inch from the storm overall. That is some torrential rain.

8:20 p.m. update: The worst of the storms are now pushing into the D.C. eastern suburbs where a severe thunderstorm warning is in effect until 9:15 p.m. A radar bow echo has formed along the line of storms sweeping across central Prince George’s County and these features are often associated with damaging wind gusts. Doppler radar indicated very strong gusts around Landover and Suitland, now pushing into Kettering and eyeing the Upper Marlboro area. Seek shelter in these areas.

Meanwhile, the worst of the storms have exited the District and most of the Beltway (except along its eastern periphery). The storms produced extremely heavy rainfall rates as they moved through which resulted in some areas of street flooding.

8:15 to 9:15 p.m. update: A severe thunderstorm warning has been issued for D.C.’s immediate eastern suburbs through 9:15 p.m. Torrential rain, dangerous lightning and pockets of damaging winds are possible. Head inside.

8:00 p.m. update: Strong storms span from Fairfax to Arlington to downtown Washington to Greenbelt to Laurel to Glen Burnie. Lots of heavy rain and lightning, and isolated pockets of strong winds. They are moving toward Burke, Alexandria, Suitland, Bowie and Severna Park over next 30 minutes.

7:45 p.m. update: A solid wall of very heavy rain accompanied by vivid lightning and booming thunder is plowing through the District and close-in suburbs. There may also be some pockets of damaging winds. The storms will take about 45 minutes to pass. Currently, the Nationals and D.C. United games are under rain delays.

7:30-8:15 p.m. update A severe thunderstorm warning has been issued for the immediate D.C. area (including all of the Beltway and the District) until 8:15 p.m. Storm moving inside the Beltway has intensified and may produce pockets of damaging wind. Head inside.

7:25 p.m. update: Storms span from near Centreville, Va. to Potomac and north Bethesda (including the northwest portion of the Beltway) to the northeast through Columbia and up to around Baltimore.  The storms are on track to push through the immediate metro area, including the District and eastern suburbs inside the Beltway over the next 60 to 90 minutes. Heavy rain and lightning are likely to be the main hazards of concern with these storms.

7:05 p.m. update: Line of storms northwest of D.C. continues advancing southeast. It has decreased a little in intensity, so there are no severe thunderstorm warnings presently in effect. However, these storms are still likely to produce very heavy rain, lightning, and pockets of strong winds.

We’re still thinking they’ll hit the north side of the Beltway around 7:20-7:30 p.m. and the District itself between 7:45 and 8 p.m. Storms take about 30-45 minutes to pass.

6:45 p.m. update: Storms northwest of the D.C. metro area span from roughly Leesburg to Ellicott City. Pockets of strong winds and perhaps some hail are embedded within this line. However, the intense storm in Howard County (mentioned in earlier update) has weakened some, though is still producing heavy rain and some strong winds.

The estimated time of arrival on the north side of the Beltway is around 7:20-7:30 p.m. give or take 10 minutes.

6:27 p.m. update: The storm moving along Interstate 70 in Howard County is quite intense, and likely contains hail, possibly large, and strong winds – in addition to torrential rain and lightning. It is closing in on Columbia and Ellicott City – likely arriving around 7 p.m.

6:10 p.m. update: An intense line of storm continues to close in on the D.C. metro area from the northwest. Severe thunderstorm warnings are out for the regions including Damascus (northern Montgomery and western Howard counties)  and Leesburg (northern Loudoun County) through 6:45 p.m.

The Beltway area should be prepared for storms moving in between about 7:30 and 8 p.m. or so.

5:45 p.m. update: A line of severe thunderstorms is moving into the region from the northwest. So far, strong and potentially damaging winds are going to be the main threat with this line, although large hail and even an isolated tornado are possible. Stay in touch with your weather sources tonight, especially if you’re leaving the house and/or getting on the road.