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 National Weather Service Storm Prediction Center has placed areas along and east of the Interstate 95 corridor under a Level 2 out of 5 risk for severe storms, including the District, Annapolis and Fredericksburg.
Regardless of if and where severe storms develop, most of the region remains under a flood watch issued by the National 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 Interstate 70 between Baltimore and Frederick. Amounts were less to the south, generally between 0.5 and 1 inches south of the Beltway, so far.
Severe weather threat summary
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.
Analysis by severe weather expert Jeff Halverson
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, then the severe weather threat may only reach as far north as Southern Maryland. If the warmer air can make it farther north, then 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, as well as 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.
