A storm system headed toward the D.C.-Baltimore area Monday night has forecasters predicting high wind speeds, large hail and the potential for multiple tornadoes in the area, bringing the region its first National Weather Service-declared Level 4 storm in more than a decade.
Monday’s storm system is the first Level 4 storm for the D.C. area since 2013.
The National Weather Service issued a Level 4 alert Monday, warning of severe storms from 2 p.m. to 10 p.m. that bring the possibility of an isolated strong tornado to the region.
A tornado watch is in effect until 9 p.m. and the NWS has said wind speeds could reach up to 75 miles per hour.
The areas at risk for severe storms span from around the Richmond, Virginia, area to northern Pennsylvania.
The area spanning from New York City to Atlanta falls within a Level 3 risk—which the National Weather Service Storm Prediction Center defines as an enhanced risk—meaning there the risk for tornadoes and damaging winds is possible but not as likely as it is in the D.C.-Baltimore Area.
Because of the fast-moving nature of the storm the risk of flooding is minimal, according to meteorologist Matthew Cappucci, though there’s some chance of a flood threat for the Delmarva Peninsula which includes Delaware and the eastern shore counties of Maryland and Virginia.
The U.S. Office of Personnel Management issued a mandate Monday that all employees of Federal agencies in the D.C. area must leave federal offices no later than 3 p.m. because of the storm.
D.C. libraries and summer camps run by the district’s Parks & Recreation Departments have also announced 3 p.m. closures because of the storm.
The National Weather Service Storm Prediction Center assesses severe storms on a scale of 1 to 5. Level 1 storms are of marginal risk whereas Level 5 storms predict high risk for severe storms to strike an area. Monday’s storm is a Level 4 risk, meaning there is a moderate risk for a severe storm that will contain damaging winds, severe hail and/or tornadoes. The NWS describes these storms as the kind you experience about once a year or less.
50 million. That’s how many people will be affected by the overall system that stretches much of the East Coast, according to the Washington Post, though the most severe portions of the storm cover the Baltimore-Washington D.C. area.
Storms of this kind are rare for the D.C. area. The last time a Level 4 risk from the National Weather Service Storm Prediction Center was June 13, 2013 when a set of storms brought six tornadoes to the greater D.C. area, according to the National Weather Service. The year before that a derecho struck the area after a moderate risk, or Level 4 risk, was issued. The storm system brought violent winds reaching 60 mph and intense thunderstorms, according to the Post. Each year there are approximately two or three dozen Level 4 risks declared across the U.S., and usually those warnings are issued in the South, the Midwest and Plains states, according to the Post.
Tornado Watch Issued Until 9 p.m. For D.C. Area; Widespread Damaging Winds Possible (Washington Post)