Updated at 4:15 p.m.
VIRGINIA — Odds for heavy rainfall late Friday into Saturday are increasing, prompting the National Weather Service to issue a flood watch for the weekend. Dry conditions that caused brush fire in Prince William County will be doused as up to 2.5 inches of rain is expected to drop on parts of Northern Virginia.
Thursday afternoon the NWS said parts of D.C., Northern Virginia and Maryland could see flooding caused by excessive rainfall. The flood watch starts at 2 a.m. Saturday and runs until 2 p.m. Saturday.
Areas included in the flood watch are: the District of Columbia, Fairfax, Arlington, Falls Church, Alexandria, Chantilly, Reston, Franconia, McLean, Centreville, Annandale, and Herndon.
Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations, the NWS said. Low-water crossings may be flooded.
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Rainfall of 1.5 to 2.5 inches is most likely late Friday night through Saturday morning, with rain expected to end Saturday afternoon. The bulk of this rain is expected to fall in a six-hour period, and may result in flooding of urban and poor drainage areas, as well as on small streams.
Visit www.weather.gov/safety/flood for flood safety and preparedness information.
Another round of rain is predicted for Tuesday night through Thursday, the weather service said.
"Widespread rain arrives from the south late Friday into Saturday as an area of low pressure lifts north from the Gulf Coast and cold front approaches from the Ohio River Valley," the National Weather Service said.
The steadiest/heaviest rainfall looks to be along and east of the Blue Ridge where 1 to 2 inches of rain can be expected. Locally higher amounts are possible along and east of the I-95 corridor, the NWS said.
Coastal flooding during high tide is possible along the mid-Atlantic coast, AccuWeather said. The heavy surf action can lead to considerable beach erosion, especially from the Carolinas to New Jersey.
Two storm systems will merge to generate drenching rain with increasing winds, building seas and rough surf from Florida to the Carolinas, Virginia, Maryland, Delaware and New Jersey from Friday to Saturday, AccuWeather said.
The mix of low clouds, rain and stiff breezes may result in airline delays, AccuWeather noted.
Here's the latest Northern Virginia forecast from the National Weather Service:
Thursday: Sunny, with a high near 47. Northwest wind 10 to 13 mph, with gusts as high as 20 mph.
Thursday Night: Mostly clear, with a low around 28. Northeast wind around 6 mph.
Friday: Mostly sunny, with a high near 51. Northeast wind 5 to 13 mph becoming south in the afternoon. Winds could gust as high as 18 mph.
Friday Night: Rain, mainly after 11pm. Patchy fog after 2am. Low around 46. Southeast wind 7 to 10 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible..
Saturday: Rain. The rain could be heavy at times. Patchy fog before 8am. High near 56. East wind 8 to 14 mph becoming north in the afternoon. Winds could gust as high as 24 mph. Chance of precipitation is 100%. New precipitation amounts between 1 and 2 inches possible.
Saturday Night: Rain likely, mainly before 8pm. Mostly cloudy, with a low around 34. Breezy, with a north wind around 22 mph, with gusts as high as 36 mph. Chance of precipitation is 60%.
Sunday: Sunny, with a high near 52. Breezy.
Sunday Night: Mostly clear, with a low around 32.
Monday: Sunny, with a high near 56.