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Heavy storms exit D.C. area; tornado watch for Southern Maryland remains

Damaging winds and a quick-hitting tornado cannot be ruled out, especially south and southeast of the District.

By Dan Stillman, Jeffrey Halverson | 2024-04-03

* Flood watch until 6 p.m. | Tornado watch in Southern Maryland and Virginia's Northern Neck until 7 p.m. *

3:55 p.m. -- Heaviest storms have pushed off to the east and south of Washington (last update)

The most intense storm activity has progressed well south and east of the Beltway and is sweeping across the bay toward the Delmarva as well as across portions of Southern Maryland and Virginia's Northern Neck. A couple of storms northeast of Richmond have triggered tornado warnings, although nothing has been confirmed.

The heaviest rain has ended in the immediate Washington area, although some showers linger. This afternoon's downpours produced about half an inch to an inch of rain in areas along and east of Interstate 95.

A few more downpours could still pass through later this evening, but severe weather is no longer anticipated north of Southern Maryland and west of the bay. This will be our last storm update. Stay tuned for the forecast for tonight and tomorrow.

1:50 p.m. -- Heavy showers and storms approaching region from southwest, flooding possible

Radar shows a large complex of showers and storms approaching the D.C. area from the southwest. It should arrive over the next hour, and rain could be heavy at times through the afternoon. Some areas could see 1 to 3 inches of rain in a short amount of time, leading to a risk of flooding. Several flood warnings for urban areas and small streams are in effect in Northern Virginia and parts of Maryland. The rain should start to exit to the northeast around 5 p.m. or so.

12:50 p.m. -- Tornado watch issued for Southern Maryland and Virginia's Northern Neck

(National Weather Service)

The National Weather Service has issued a tornado watch, in effect until 7 p.m. Eastern time, for much of eastern Virginia, Southern Maryland and most of the Delmarva Peninsula. The watch area includes Richmond and Salisbury, Md.

It does not include the Washington and Baltimore Beltway areas but locations to the south and southeast, including Calvert and St. Mary's counties in Maryland and King George County in Virginia's Northern Neck.

"Scattered severe storm development is expected this afternoon along and east of a surface front and deepening cyclone moving across Virginia," the Weather Service's Storm Prediction Center wrote. "The storm environment will favor a mix of line segments and supercells capable of producing a couple of tornadoes, damaging gusts of 60-75 mph, and isolated large hail of 1-1.5 inches in diameter."

Even though the immediate D.C. and Baltimore areas aren't included in the watch, storms with heavy downpours and gusty winds cannot be ruled out, and a flood watch remains in effect through the afternoon.

Original article from midmorning

Model forecast of radar for 11 a.m. to 5 p.m. Wednesday. Universal time is displayed; subtract five hours for Eastern time. (StormVistaWxModels.com)

Numerous showers and thunderstorms will continue to move through the D.C. area through Wednesday afternoon, producing downpours at times, with flooding possible in some spots. During the afternoon, mainly between noon and 5 p.m., there's a chance that some storms could turn severe. That means there is potential for damaging thunderstorm winds and tornadoes that can form rapidly with little warning.

While we can't rule out these severe storms occurring anywhere in the region, the highest chance of seeing them is south and southeast of the Beltway, especially in Southern Maryland, where a push of warm air from the south could boost temperatures to near or above 60 degrees. Warmer air provides more fuel for severe storms, but as of midmorning, temperatures across the region were in the chilly mid-40s to near 50.

The Storm Prediction Center has placed areas along and east of the I-95 corridor under a Level 2 out of 5 risk for severe storms, including the District, Annapolis and Fredericksburg.

Risk of severe storms on Wednesday. (National Weather Service)

Regardless of if and where severe storms develop, most of the region remains under a flood watch issued by the Weather Service through Wednesday afternoon. Flooding is a concern due to all of the rain that has already fallen in recent days and the potential of Wednesday's storms to produce heavy rain at rates of 1 to 2 inches per hour.

"Repeated rounds of rain and storms over the past two days has saturated the ground, especially north of US-50. As additional widespread heavy rains occur this morning and afternoon, the threat for flooding is expected to increase," the Weather Service said.

Through 10 a.m. Wednesday, most areas around the Beltway had received about an inch of rain since Monday; amounts climbed to around 2 inches along and north of I-70 between Baltimore and Frederick. Amounts were less to the south, generally between half an inch to an inch south of the Beltway.

Timing for potential severe weather: Noon to 5 p.m.

Location of potential severe weather: Possible anywhere in the region, but highest in southern/southeastern areas, including southern Prince George's, southern Anne Arundel, Calvert, St. Mary's, Charles, Stafford and King George counties.

Main severe threats: Damaging winds, tornadoes.

A stubborn wedge of chilly, rainy air may be invaded and eroded by a southerly push of milder, more unstable air, ahead of an approaching cold front. Higher up in the atmosphere, a potent jet stream with intense winds and a pocket of energy will spread over the area from the west. These features may set the stage for a brief round of severe weather.

The major uncertainty lies with how far north and west a nose of mild air coming from the south makes it. If the chilly wedge of air in place over the immediate D.C. area stays strong, the severe weather threat may reach only as far north as Southern Maryland. If the warmer air can make it farther north, there is a brief window for severe storms in and around D.C.

A few weak tornadoes are possible, in addition to scattered instances of damaging wind, with any severe storms that develop. Flash flooding and lightning remain a persistent threat area-wide.

The rule of thumb today is that our chances of severe weather generally increase from northwest to southeast across the region.


This article was downloaded by calibre from https://www.washingtonpost.com/weather/2024/04/03/washington-dc-severe-storms-tornadoes-flooding/


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