PM Update: Pockets of heavy rain, flood risk this evening; drying out Friday

9 p.m. Update: No severe warnings are currently in effect across the D.C. area. Scattered pockets of moderate to heavy rain continue, but should diminish after 10 p.m. or so. Here’s what it looked like on the G.W. Parkway earlier this evening…

8:15 p.m. Update: The Flash Flood Warning north and west of town has been cancelled, as rain has largely stopped in the previously warned area. Pockets of heavy rain, mainly outside the Beltway for the time being, will continue to impact parts of the area during the next few hours.

6:10 p.m. Update: A Flash Flood Warning is in effect until 9 p.m. north and west of D.C. in southern Montgomery, northwestern Fairfax, and southeastern Loudoun counties. Extremely heavy rain is falling in the warned area and could continue for a while. The warning calls for a possibility of 2 inches and we wouldn’t be surprised if some spots pick up more than that. Turn around, don’t drown if confronted with standing water.


Radar & lightning: Latest regional radar shows movement of precipitation and lightning strikes over past two hours. Refresh page to update. Click here or on image to enlarge. Or see radar bigger on our Weather Wall.

From 4:30 p.m… Temperatures have dropped a hair compared to yesterday, but humidity levels remain high.  Meanwhile, a stalled, fading front is serving as a focus for the development of storms this evening, which may be intense.  As steering currents are weak, heavy rain could fall in some areas for a long duration, posing a flash flood threat.  On Friday, weak high pressure moves in, shutting down the rain threat.

Through Tonight: Isolated showers and storms, locally heavy, may develop this evening.  Storms may become more widespread between 6 p.m. and midnight.  A few storms could produce strong wind gusts and small hail.  The more likely hazard is isolated to scattered flash flooding in the heavier storms due to their slow movement, with rainfall rates up 2 inches per hour possible.  Rain should diminish in coverage and intensity after midnight, with slow, partial clearing.  Lows range from the mid-60s in the cooler suburbs to the low 70s downtown.

Tomorrow (Friday): Partly sunny with moderately high humidity – similar to today.  But rain chances are slim to none as today’s rainy front will have moved off to the south and southeast.  Highs are seasonable, in the mid-to-upper 80s. Winds are generally light from the north-northeast at 5-10 mph.

See David Streit’s forecast through early next week. And if you haven’t already, join us on Facebook and follow us on Twitter . For related traffic news, check out Dr. Gridlock.

Simulated radar from HRRR model at 7 p.m. ET.  This is a model forecast and may not reflect reality.  (WeatherBell.com)

Simulated radar from HRRR model at 7 p.m. ET. This is a model forecast and may not reflect reality. (WeatherBell.com)

Pollen update: Tree/grass/weed counts are LOW.  Mold spores are MODERATE-HIGH.

Weather does not cause your back pain: Lenny Bernstein, on the Post’s To Your Health blog, writes: “…in a new study released Thursday, a team of Australian researchers compared the onset of low back pain among 993 patients with meteorological records. They found no connection between back pain and changes in temperature, humidity, air pressure, wind direction or precipitation.” Full story: No, Uncle Fred, the weather has nothing to do with your back pain

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