The heaviest rain is moving out of the D.C. area as residents brace for potential flooding Tuesday after a recent stretch of dry weather.
And the forecast calls for another round of storms later in the day.
- Flood warning for parts of Maryland until 11:30 a.m.
- Flood watch for most of the region lasts until 2 p.m.
- Flood threat lingers until the afternoon.
- Risk of evening storms
The National Weather Service issued a flood watch for most of the D.C. region until 2 p.m.
A flood warning was also issued for parts of central Maryland and north central Maryland until 11:30 a.m. Some of the counties impacted include Howard, Montgomery, Carroll and Frederick. During a warning, flooding is imminent or occurring.
As rain continues to move Northeast, StormTeam4 Meteorologist Chad Merrill said flash flooding is likely in some areas north of the District on Tuesday morning.
“There will be short-term rises on streams and creeks, but we are not seeing a risk so far this morning for any river flooding,” Merrill said. “Most of this is likely due to the recent dry stretch of weather.”
Merrill said drivers should watch for pockets of water on roadways.
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Temperatures will rise to the mid 80s as the day goes on.
Low pressure pushing across the region is responsible for spouts of heavy rain, Merrill said.
The showers and storms were expected to drop up to 3 inches of rain, with some isolated areas receiving 4 inches. By 6 a.m., 2 inches had already fallen in some areas.
By the afternoon, there should be some sunshine peaking through the clouds.
Tuesday evening could bring more challenges to commuters — scattered thunderstorms re expected.
The wet weather should wrap up Tuesday night, but return on Wednesday as a front from Pennsylvania pushes south toward the District. Flooding isn’t expected though, Merrill said.
Dry weather returns Thursday and it should be comfortable through Saturday.
Rainfall reports across the region as of around 6 a.m., according to Merrill:
- Leesburg in Loudoun County, Virginia: 2.16 inches
- Ijamsville in Frederick County, Maryland: 2.04 inches
- Gaithersburg in Montgomery County, Maryland: 1.84 inches
- Germantown in Montgomery County, Maryland: 1.72 inches
- Sykesville in Carroll County, Maryland: 1.32 inches
- D.C.: 0.22-0.39 inches
The weather in context
The rain comes after a dry stretch of weather in August.
Rain totals in August were 0.83 inches below average coming in at 2.42 inches, while the average is 3.25 inches at Reagan National. Totals were far below last year which ranked as the fourth wettest August on record with 9.07 inches.
But its been weeks since the last time the region had significant rainfall, Merrill told WTOP. The most recent appreciable rain in D.C. (with more than half an inch) was on Aug. 10 with just 0.52 inch.
Since Aug. 15, things have been pretty dry.
The risk for flooding is often determined by what the weather is like before the rain, particularly this time of year, Merrill said.
“If we would have seen a super wet August, especially focused during the month’s second half, then widespread flooding would likely be occurring across the region here this morning,” Merrill said.
The wettest month of the year on average in D.C. is July, followed by June, May and September. September ranks just 0.01 inch below May’s average rainfall of 3.94 inches.
Though it’s been relatively dry in recent weeks, Merrill said this past July was the 13th wettest in D.C. since 1870 with 7.61 inches.
Tuesday: Cloudy with heavy showers. Flooding possible. Highs: Low 80s.
Wednesday: Early showers, then mostly cloudy. Highs: Upper 80s.
Thursday: Partly sunny. Highs: Around 80.
Friday: Mostly sunny. Low humidity. Highs: Low 80s.