5:10 p.m. update: After a few scattered showers, the immediate D.C. area has a break in the action, although heavy rain continues to drench western Loudoun and Frederick counties where over 1 inch has fallen in some spots. Flooding may start to be an issue there with more bands of showers coming in from the south.
For the immediate D.C. area, it looks like our steadiest rain accompanied by gusty winds will come in between 9 p.m. and 3 a.m. tonight. Follow this link for more information and additional updates: PM Update: Heavy showers and gusty winds overnight; much colder Thursday
4:50 p.m. update: While we await whether the National Weather Service decides to issue a severe thunderstorm watch for later this evening, showers - some heavy - continue from Baltimore back to Leesburg. Allow some extra time driving on I-270 and 70. Some spots have received 0.5-1 inch of rain. This activity should slowly lift northeast as we watch the next big batch from the southwest (see below) gradually approach.
Today’s high temperatures were very mild. In addition to the record high of 72 set at Dulles Airport mentioned below, Reagan National also hit 72, but shy of its record of 77 from 2002.
4:15 p.m. update: Some heavier showers and storms in southwest Va. (see above image) may head northeast towards the D.C. area later this evening. The National Weather Service Storm Prediction Center says there is an 80 percent chance it will need to issue a Severe Thunderstorm Watch for this activity for the District and points south. This activity, should it hold together, would impact the region between 8 p.m and midnight.
We still don’t favor widespread severe activity around D.C. though generally gusty winds (note: wind advisory) and downpours are certainly a good possibility.
4:00 p.m. update: Dulles Airport hit at least 72 degrees today, breaking the record for the date of 70 (set in 2002).
Overview: A powerful cold front is plowing towards the East Coast with a long line of showers and thunderstorms along and ahead of it. Some of this activity is severe. In the D.C. area, the mains risks are strong winds of 35-50 mph, with isolated gusts to 60 mph possible.
Isolated to scattered power outages are possible, but this is storm system will not pack the punch of the June 29, 2012 derecho. In addition to gusty winds, isolated flash flooding is possible.
The time window for the heaviest rain and strongest winds spans from 3 p.m. to 7 p.m. from west to east in the D.C. area (probably 4-6 p.m. or so around the beltway). However, additional rain showers and gusty winds are likely to continue for several hours beyond that. More details: Squall line poses heavy rain and strong wind risk tonight for Washington, D.C. area
Previous updates (no longer current)
3:50 p.m. update:Gusty showers continue , mainly north of the beltway and extending southwest into Loudoun county. Some showers developing southwest of town are headed into Fairfax county and may dampen the District in the next hour. We still have no reports of severe weather and are not expecting a widespread severe outbreak. However, winds are likely to increase this evening as the front draws closer and rains will also gradually increase in coverage.
3:30 p.m. update: A wind advisory has been issued through 6 a.m. for sustained winds of 25 to 35 mph and gusts up to 45 to 50 mph. These winds are associated as much with the incoming front as they are with any gusts associated showers moving through. Isolated power outages could result.
3:15 p.m. update: The National Weather Service has reduced the odds of damaging winds associated with storms from 30 percent to 15 percent (within 25 miles of a point) in the D.C. metro area.
3:10 p.m. update: Line of showers/storms stretches from northern Baltimore county through western Montgomery and central Loudoun counties and and to the southwest. Still no reports of severe weather, but the northern half of the line could generate gusts over 40 mph.
Showers/storms should edge closer to the immediate D.C. area (inside the beltway) in the next hour, with activity favored around 5 p.m. or so. This estimate may need to be refined depending on how showers/storms evolve.
2:55 p.m. update:Line of heavy showers stretches from northeast Carroll county to northwest Montgomery couny and is headed northeast towards western Baltimore and Howard counties. Wind gusts of 30-45 mph are possible. I should stress that while these are gusty showers with heavy downpours, so far indicators do not suggest widespread severe, hazardous weather with this activity.
2:30 p.m. update: The strongest showers/storms in central Loudoun and Frederick county are lifting north-northeast towards western Montgomery, Carroll and Howard county. Leesburg should get some gusty showers in the next 20 minutes. Additional, lights showers are forming to the southwest. None of this activity is severe but should produce gusty winds as it cycles through. Activity is not imminent for areas inside the beltway and to the south and east.
2:15 p.m. update: The line of showers/storms is about to move into Frederick, Maryland with downpours and gusty winds, probably reaching 30-40 mph. It’s also closing in on Purcellville in western Loudoun county and is probably 30-45 minutes from Leesburg.
2:00 p.m. update:The warm before the storm - temperatures are right around 70 degrees (71 at Dulles and 69 at BWI airports) except near water. At Reagan National, its proximity to the cool Potomac has the 2 p.m. temp at just 63.
1:50 p.m. update: So far, I have not seen any reports of severe weather with this line of gusty showers west of D.C. out towards the Blue Ridge. It’s a different story in north Georgia, where a large tornado killed at least one person and overturned numerous cars in Adairsville, which is 61 miles northwest of Atlanta. Watch an incredible video.
1:45 p.m. update: The line of showers and storms has crossed I-81. In Hagerstown, meteorologist Alan Auglis said winds gusted to 31 mph with a “drenching rain.” Facebook reader Seth Gooding described “crazy rain” in Winchester with wind gusts estimated at 30 mph off and on.
1:25 p.m. update:A line of strong showers and storms is approaching the 1-81 corridor, closing in on Hagerstown, Martinsburg, and Winchester in the next 30 to 60 minutes. These areas can expect heavy rains and wind gusts to 35-50 mph.