UPDATE, midnight: An isolated thunderstorm with heavy rain and frequent lightning (but no evidence of strong winds) developed over Arlington and has moved into the southern half of the District and central Prince George’s county. The lightning has, apparently, triggered some power outages in Arlington.

Some additional isolated to scattered storms are possible overnight - especially in northern Virginia, with the best chances along and south of I-66. Radar shows storms developing west of Fauquier county.

UPDATE, 6:30 p.m.: There’s still the outside chance of an isolated pop-up thundershower, but storms are done by and large. We’ll keep you posted about any activity that pops up on the Twitter feed above and, if there’s anything major, will post an update here.

The severe thunderstorm watch has been discontinued in northern counties and will probably be canceled progressively south in the next couple of hours.

UPDATE, 6:10 p.m.: Storms out to west around Clark and Loudoun county are fading and may not make much further progress east. Rain chances are diminishing but not entirely eliminated in the immediate area. We will keep you posted if any new storms pop up.

Strong to severe storms continue affecting parts of southern Maryland and the northern neck of Virginia but should move off in the next hour.

Link: Earlier updates (no longer active)

Overview, 2 p.m.: As the region’s temperatures soar past record-breaking territory, a cold front is sagging southward from near the Mason Dixon line. Maryland, northern Virginia, and West Virginia lie in the battle ground between the scorching hot and cooler air where severe thunderstorms are possible.

A severe thunderstorm watch is in effect for the entire D.C. and Baltimore metro region through 10 p.m. tonight. Large hail and damaging winds to 70 mph are possible in thunderstorms that develop. Dangerous lightning and torrential rain is likely in most storms.

Remember a severe thunderstorm * watch * means severe thunderstorms are * possible * (not guaranteed). A * warning * indicates severe storms are imminent and you should seek shelter.

Timing: Storms are most likely to reach the western and northwest suburbs (west of the beltway) between 2:30-4:00, the immediate D.C. area (including the beltway) between 3:15 and 4:45 p.m. and the eastern suburbs (east of the beltway) from 4:00 to 5:30 p.m. These times approximate and may require tweaking. Monitor updates above..

Expired updates from earlier:

UPDATE, 5:50 p.m.: While strong to severe storms drift southeast towards the northern neck of Va. and southern Md., we’re still watching a small cluster of storms in Clark and western Loudoun county which are slowly tracking towards to the east. They could move into western Montgomery county in the next 30-45 minutes but are not particularly strong.

Also, thunder and lightning are occurring around the metro region even though it isn’t raining, so stay indoors or in a car if possible.

UPDATE, 5:30 p.m.: A severe thunderstorm warning is in effect for eastern Charles, northwest St. Mary’s and central Calvert county through 6:15 p.m.

UPDATE, 5:10 p.m.: Most of the strong to severe thunderstorm activity has now moved well south and southeast of the District. The most intense activity stretches from southeastern Prince William county (east of Dale City) to southern Stafford county and is headed towards the Fredericksburg area and Charles county. A severe thunderstorm warning is in effect for these areas through 6:15 p.m. These storms have a history of producing hail and some wind damage according to the National Weather Service.

Frequent question: is the storm threat over around D.C.? The metro region isn’t completely out of the woods this evening - especially in northern Virginia - as some more storms are developing out around Winchester and moving east/southeast. Also, some isolated pop-up storms could develop with little warning. Generally speaking, the storm threat decreases as you head north though.

UPDATE, 4:40 p.m.:If you live north of the District, you’re in the clear - at least for now. The heaviest activity right now is in southeast Fairfax county (around Franconia and Mt. Vernon), heading southeast towards western Charles county (where a severe thunderstorm warning is now in effect) and in extreme southern Fauquier county moving towards central Stafford county. Generally speaking, there haven’t been a lot of severe weather reports with these storms, but dangerous lightning and locally strong winds are possible.

UPDATE, 4:25 p.m. A severe thunderstorm WARNING is in effect for eastern Fairfax county, the District, southern Montgomery and southern Prince George’s county through 5 p.m. Storm may produce damaging wind gusts to 60 mph ESPECIALLY in southern part of this area around Springfield and south Alexandria.

UPDATE, 4:20: A benefit of these storms is the drop in temperatures behind them. Hearing about 20 degree drops in a few minutes.

UPDATE, 4:05: Strong-severe storm now passing through Reston and Great Falls is headed towards Falls Church, Arlington, Springfield, and Alexandria in next 30 minutes or so. It’s grazing southern Montgomery county and may brush the District as well in this span. Downpours and dangerous lightning will accompany these storms as well as some gusty winds.

A very strong thunderstorm cell in northern Fauquier and southern Loudoun county is pushing through Middleburg and the Plains and should reach Warrenton around 4:15 or 4:30. This storm has a history of producing hail. A severe thunderstorm warning is in effect for this area (into central Fauquier and northwest Prince William co) through 4:30 p.m.

UPDATE, 3:50: A severe thunderstorm warning has been issued until 4:30 for storm currently near Herndon, moving SE at 25 mph towards Great Falls, Reston and Wolf Trap. Winds to 60 mph are possible with this storm along with dangerous lightning.

UPDATE, 3:45: Strong storm that passed thru Leesburg & Ashburn in last half hour is heading towards Herndon & Reston next 15-30 mins. Gusty winds, lightning and downpours are possible. But this storm is not - at present- classified as severe.

UPDATE, 3:30: So far, not seeing a lot of severe weather reports with these storms - and they’re waxing and waning in intensity. The storm that passed through Leesburg has weakened some and should move into western Fairfax county in the next half hour. The most impressive storm is located near the intersection of Clark, Fauquier and Loudoun county per the warning information below. It’s headed towards Middleburg, Va in the next 30-45 mins.

UPDATE, 3:20: Severe thunderstorm warning for NW Fauquier & SW Loudoun co thru 3:45.

UPDATE, 3:05: Note: these storms developing to the northwest may produce strong, damaging winds in a few spots, but this is NOT on the scale/intensity of 6/29 derecho.

UPDATE, 2:55: A severe thunderstorm WARNING is in effect for eastern Loudoun and western Montgomery county through 3:45 p.m.

UPDATE, 2:50:Strong storms continue to develop and track along the Potomac river from the eastern panhandle of West Virginia into southern Frederick and northern Loudoun county. These storms are moving southeast at 25 mph towards the D.C. area. They’re currently about 30-45 mins from Leesburg and Poolesville.

UPDATE, 2:30: Strong to severe storms are moving into west and northwest outlying areas. A severe thunderstorm warning is in effect for northern Loudoun and southern Frederick county through 3 p.m.