Severe Weather in the Mid-Atlantic Region

Preliminary April 26 Severe Weather Reports (NOAA)

Although the spring is the busiest time of the year for severe weather nationally, Maryland and Virginia typically see a higher amount of severe weather – tornadoes in particular – during the summer.  According to 20-year NOAA averages through 2010, the United States averages more than 1,200 tornadoes annually.  Looking more closely at the data, the months of April, May and June have the highest average number of tornadoes of any three-month period during the year.  Maryland averages 10 tornadoes while Virginia has an annual average of 18 tornadoes. 

In the Mid-Atlantic Region, the highest average number of tornadoes occur in July, August and September.  Part of that is because the weather is warmer and more humid during the summer months which can be more conducive for thunderstorm development.  It also includes the possibility of tornadoes from decaying tropical systems.  There have been a number of former tropical systems during the past twenty years to impact the DC Metro Region with heavy rain, gusty winds, coastal flooding and severe weather – including Fran in 1996, Floyd in 1999, Isabel in 2003 and Irene in 2011.

Meanwhile, the Washington, D.C. – Baltimore corridor has had some significant severe weather events in April during the last fifteen years.  Most recently in 2011, when a total of 19 tornadoes touched down in Maryland and Virginia on April 27-28.  Those tornadoes were a part of a larger four-day severe weather outbreak that occurred from the central United States to the East Coast.  That was one of the highest overall occurrences of tornadoes in the DC Metro Region to occur since April 20, 2008 when nine tornadoes were observed in Maryland and Virginia.

This week also happens to mark the 14^th anniversary of Maryland’s strongest tornado on record. Longtime residents will recall that a powerful F4 tornado touched down in La Plata, Maryland on April 28, 2002.  Although there was advance warning for this storm, this tornado was still damaging and deadly because of its unusual intensity for this part of the country.  During just the last twenty-four hours there has been another significant late April severe weather outbreak.

NOAA’s Storm Prediction Center reports more than 600 cases of severe weather occurred yesterday from Texas to West Virginia.  Such severe weather outbreaks reinforce the need to stay informed of the latest weather conditions.  Social media and smart-phone apps make that easier in 2016 – whereas that wasn’t possible for the La Plata storm in 2002.  Being aware of the latest weather conditions is only part of the story.  Knowing what to do when severe weather or flash flooding threatens your area is equally important to ensure your safety.