4 p.m. - Flash flood watch canceled
Radar shows rain associated with Florence’s remnants have pushed well southeast of the immediate D.C. area push through Southern Maryland and over the Delmarva. Washington can finally start to dry out.
Original post from midday...
Heavy showers and storms drenched the Washington region Monday night, causing some streams and creeks to overflow. We’ve lost count of how many times we’ve seen this scenario play out since May.
Another round of showers and storms may lead to a repeat this afternoon.
Compared with Monday’s activity, today’s is likely to be less widespread and intense. The most numerous showers and storms may focus in our eastern areas, especially toward southern Maryland and over the Delmarva Peninsula.
However, because the ground is saturated and waterways are swollen, it won’t take much to spur more flooding.
A flash flood watch is in effect until 6 p.m.
The rain so far
Since Florence’s remnants began affecting the region, Washington has received 1.36 inches of rain, the bulk of it falling in two rounds of storms, the first Monday evening around 5 p.m. and the second around midnight Tuesday. Some locations just north of the District, including around Laurel, received up to 3 to 4 inches.
Monday marked the 18th day this year Washington has received at least an inch of rain, which ranks second most on record year-to-date, behind 1886 (which had 19 through Sept. 17), according to Capital Weather Gang’s Ian Livingston.
The soaking pushed Washington’s 2018 rainfall total over 47 inches, about 19 inches above normal, third-most on record year-to-date, behind 1886 and 1889.
Monday night’s rain spurred areas of flash flooding, including over Northwest D.C., where a flood warning was issued around Rock Creek Park.
“I’ve been running this path heading toward P street in Rock Creek Park 5 to 6 times per week for 10 years and I’ve never seen it this high in the morning,” wrote Brittany Meyer, in email.
The overnight storms not only featured heavy rain but also deafening thunder that awakened many from their sleep.
“It was insane! Huge claps of thunder right alongside the lightning,” tweeted Capital Weather Gang Twitter follower Jess.
“Good lord, that was one of the loudest thunder claps I’ve ever heard,” added Robert Lintott, tweeting from Mount Pleasant.
Tuesday’s rain potential
Short-term models showing widely scattered showers and storms this afternoon, mostly focused along and east of Interstate 95. The official National Weather Service forecast suggests 0.5 to 1.0 inches could fall in this eastern zone, although amounts will be highly variable depending on where this hit-or-miss activity materializes.
Compared with Monday, when some storms were rotating, triggering tornado warnings, we do not expect a repeat today.
Showers and storms should exit our eastern areas, including Southern Maryland, by 6 p.m. or so but may continue over the Delmarva Peninsula, pushing west to east off the Atlantic Coast by about 10 p.m.