Rain complex hits D.C. area at lunch time


Radar & lightning: Latest D.C. area 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.

Overview: An area of rain/storminess, known as a mesoscale convective system, will zip through the Washington, D.C. metro area between roughly 11:15 a.m. and 2:30 p.m. this afternoon. Heavy rain, some thunder and lightning, small hail, and gusty winds to 30-40 mph are possible as these storm pass. The storms should stay below levels considered “severe” (wind gusts over 58 mph and hail at least half an inch in diameter). A quick half-inch of rain, with locally higher amounts, is possible over the region. It is likely to delay the 1:05 p.m. start of the Nationals game on “weather day” at Nationals Park. Follow below for the latest updates.

2:00 p.m.:  I-95 is the rough dividing line between rain and no rain.  The showers will rapidly exit our eastern suburbs in the next 30 minutes. This is our last update.

1:20 p.m.: Back edge of rain is eroding fast – already into Fairfax County on the southside, and Frederick, Md. on the north side.  Areas inside the Beltway have another 20-30 mins of rain. Then it’s over.

1:05 p.m.: The thunderstorm activity associated with this complex has weakened, and it has mostly evolved into a plain rain system.  Most of the thunder/lightning was along the leading edge, which has passed.  The back edge of the rain has reached Frederick and Loudoun County and rain should taper off per the times estimated in our 12:35 p.m. update below.

12:35 p.m.: When does it end? Simulated radar from the HRRR model shows the complex pushing into our eastern suburbs by 2 p.m. and out of the region by 3 p.m.  Our western suburbs should be done with the rain around 1:15-1:45 p.m., the immediate metro region between 1:45-2:15 p.m., and our east suburbs between 2:15 and 2:45 p.m.  Such simulations aren’t perfect so allow an error of around 15-30 minutes on either side of these time windows.

Simulated radar from HRRR model at 2 p.m. (WeatherBell.com)

Simulated radar from HRRR model at 2 p.m. (WeatherBell.com)

12:15 p.m.: Here’s a radar close-up of the storm complex as of 12:08 p.m.

(RadarScope)

(RadarScope)

11:57 a.m.: Scattered showers and storms have broken out throughout the area, ahead of the original main batch of rain now from around Dale City to Fairfax to Potomac.  The next hour or two will be thundery and wet, but I haven’t seen reports of strong winds or hail.

11:44 a.m.: A few front-running showers/downpours have developed ahead of the main complex inside the Beltway around Tysons and Arlington.  These will move into the District, momentarily.

11:32 a.m.: Rain is now moving into eastern Loudoun and western Montgomery County.  It should arrives in the Germantown to Gaithersburg area in the next 15 minutes, western Fairfax County around 11:45, and move inside the Beltway by noon.

Facebook readers report thunder, lighting, and heavy rain in Bluemont and Leesburg in Loudoun County, as well as Urbana in eastern Frederick County (Md.).

11:22 a.m.: Facebook reader Rob Pond reports: “Moderate rain and a couple cracks of thunder in Ballenger Creek part of Frederick.”

11:20 a.m.: Capital Weather Gang is representing at Nationals Park for “weather day”.  That is sure to bring the rain, right?

11:10 a.m.: Here’s a radar snapshot from 11:07 a.m.:

(Radarscope)

(Radarscope)

11:05 a.m.: Radar shows the leading edge of the showers and storms into Frederick, Md. and moving into Leesburg, Va.

Also on Capital Weather Gang

D.C. area forecast: Cloudy day with midday storm risk before much warmer 80s