Although we cannot rule out the possibility of such severe storms occurring anywhere in the region, they are most likely to occur south and southeast of the Beltway, particularly in southern Maryland, and The push of warm air from can cause temperatures to drop to near or near zero. Over 60 degrees. Warmer air provides more fuel for severe storms, but as of mid-morning, temperatures across the region were in the chilly mid-40s to near 50 degrees.
The National Weather Service Storm Prediction Center has designated areas along and east of Interstate 95, including the District, Annapolis and Fredericksburg, as a Level 2 out of 5 risk for severe storms.
Regardless of whether a severe storm develops, most of the area remains under a National Weather Service flood watch until Wednesday afternoon. Flooding is a concern due to the rain that has already fallen in recent days and Wednesday's storm could dump heavy rain at a rate of 1 to 2 inches per hour.
“Repeated rain and storms over the past two days have saturated the ground, especially north of Highway 50. Further widespread heavy rain this morning and afternoon is expected to increase the threat of flooding. ”, the weather bureau said.
By 10 a.m. Wednesday, most areas around the Beltway had received about an inch of rain since Monday. Along and north of Interstate 70 between Baltimore and Frederick, that amount rose to about 2 inches. Volumes have been lower in the south, typically between 0.5 and 1 inch south of the Beltway so far.
Overview of Severe Weather Threats
Possible periods of bad weather: From noon to 5pm
Locations with potential for bad weather: Although it can occur anywhere in the region, it is highest in southern/southeast regions such as southern Prince George's County, southern Anne Arundel County, Calvert County, St. Mary's County, Charles County, Stafford County, and King George County .
Main serious threats: Harmful winds, tornadoes.
Analysis by severe weather expert Jeff Halverson
Prior to the approach of a cold front, a stubborn wedge of cold, wet air can penetrate and erode as calmer, more unstable air pushes in from the south. High in the atmosphere, a powerful jet stream with strong winds and energy pockets will spread over the region from the west. These features can set the stage for short periods of severe weather.
The main uncertainty lies in how far north and west the nose of calm air coming in from the south will reach. If the wedge of cold air just above Washington, D.C., remains strong, the threat of severe weather may only extend as far north as southern Maryland. If the warm air can move further north, there is a short-term chance of severe storms in and around Washington, DC.
A severe storm could produce a few weak tornadoes in addition to scattered wind damage. Flash flooding, as well as lightning, remains an ongoing threat across the region.
The rule of thumb today is that the chance of severe weather will generally be higher across the region from the northwest to the southeast.