Beware tornadoes in the DMV

 

July 1, 2021 severe weather reports (Source: NOAA)

The Mid-Atlantic Region sees most of its severe weather in May and June, with a secondary peak in the fall as the seasons begin to change. The remnants of tropical systems can also spawn tornadoes when they impact the Mid-Atlantic Region, such as with Hurricane Isaias in 2020. 

Tornadoes associated with decaying tropical systems are typically weaker than those that develop within supercell thunderstorms. Tornadic thunderstorms are exceedingly rare within DC city limits, with only five since 1950. The most recent occurrence was on July 1, 2021, when an EF-0 and an EF-1 occurred.   

Two more EF-0 tornadoes occurred in the nation’s capital on April 6, 2017. They caused only minor damage and, fortunately, no fatalities. These tornadoes occurred as part of a larger, three-day severe weather outbreak. From April 4 through April 6, 2017, there were 550 reported cases of severe weather from the Midwest to the East Coast, which included 30 tornadoes. These were the first tornadoes in the nation’s capital since September 24, 2001. DC’s strongest tornado on record was an F3 that developed in Rock Creek Park on April 5, 1923.

Maryland has had three significant tornadoes in the last 30 years. An exceptionally rare F4 tornado developed in Charles County on April 28, 2002. This tornado had a track that spanned nearly 70 miles. It reached its peak intensity as it passed through the town of La Plata with winds of nearly 260 mph. It caused more than $100 million in damage (unadjusted for inflation), in addition to five fatalities and dozens of injuries, according to NOAA. The 2002 La Plata tornado remains the strongest tornado on record in Maryland.

The town of College Park, Maryland saw a F3 tornado on September 24, 2001. Tragically, two sisters, who were students at the University of Maryland, lost their lives during this tornado, which also caused extensive damage. In addition, an F4 tornado occurred on June 2, 1998 in Frostburg, Maryland. Wind speeds of the Frostburg tornado were estimated to be as high as 210 mph.

According to NOAA data, Maryland averages between six and 10 tornadoes annually, while Virginia sees close to 20. The two strongest tornadoes on record in Virginia were F4s. One occurred on August 6, 1993, and the second on September 24, 2001.  

Tornado intensity is measured on the Fujita Scale that was named after the late Dr. Ted Fujita of the University of Chicago who designed it in 1971. It has since been updated and became the “Enhanced Fujita” or EF scale in 2007.