For the most part, the DC area has avoided severe storms and flooding as the heaviest activity remains in the north and northeast. Many areas, from northeastern Maryland to New York state, have faced flash flood warnings because of short-term heavy rainfall.
For the rest of this afternoon and evening, after the eastern I-95 exit areas see heavy rain for the next hour or so, conditions are mostly dry with temperatures around 70 degrees Celsius. A torrential downpour was not unexpected.
Total precipitation varies widely, ranging from 0.1 to 1.0 inches, but is higher locally in the east and northeast of the County.
Original post from early afternoon
Today’s main storm current is moving eastward towards the DC area this afternoon. It will affect western areas at the earliest, while east of town could be affected later — perhaps near 8pm. The sunniest locations are at greater risk of strong storms. Protracted rain is possible after the severe thunderstorm warning ends, flood watch in effect until 22:00.
Through tonight: Lightning and the heaviest downpours with the potential to cause flooding can last until 22:00 and subside a bit after that. In any given location, heavy rain can last about an hour to an hour and a half. Damage winds above 57 mph are likely to be limited to the main storm current moving eastward through the area until around 8 p.m. and could target the sunniest areas this afternoon. Most locations have a more than 50 percent chance of seeing rain. The sultry low temperatures will hover in the mid-60s to around 70 degrees.
See Current weather at The Washington Post.
Monday tomorrow): Rapid showers or storms can occur at any time, but the chance of precipitation will decrease during the day and sunshine will increase. Heat index values should remain below 90 degrees due to the lower dew point (mid-60s) combined with cooler highs in the mid-80s. Light northwesterly winds can occasionally blow to a speed of about 15 mph.
Overnight, we’ll finally be quiet under clear skies, with low temperatures cooling from the mid-60s to around 70 degrees, thanks in part to gentle (drier) winds from the northwest.
Today’s storm has the potential to cause flooding and wind damage
A severe thunderstorm warning is in effect until 8 p.m., in addition to warnings already in place north and south of the central DC area. The chance of wind damage from any severe storm subsides after 7pm in the south and east of town – but the threat of torrential downpours won’t subside until after 10pm
Here’s a county-by-county estimate of the duration of the main storm stream, which can have winds in addition to heavy rain:
- 1 to 4 p.m.: Fauquier and Loudoun
- 2 to 5 p.m.: Carroll, Fairfax, Frederick, Howard, Montgomery, Prince William, Stafford
- 2:30 to 5:30 pm: DC, Arlington, Alexandria, Prince George’s, Charles
- 4 to 8 p.m.: Anne Arundel, Calvert, St. Mary’s
The biggest threat tonight is thunderstorm flooding, identified with a probability of more than 40%, highlighted below in a “moderate” orange-red shade.
After the main flood threat from these storms this afternoon and tonight, gusts (above 57 mph) are the next likely threat. See the area marked in yellow in the bottom right panel of the map below. This suggests at least a 15 percent chance of wind damage. In the upper left panel, areas highlighted in yellow have a 40% chance of seeing severe storms today.
Remember: Turn around—don’t drown! Never approach or attempt to pass through flooded areas. We’ll talk more about this tonight in our Sunday Sunset Live Q&A. Tune in at 8:36pm
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