A closer look at tornadoes in the DMV

 

July 1, 2021 severe weather (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 change. The remnants of tropical systems can also spawn tornadoes when they impact the Mid-Atlantic Region, such as with Hurricane Ivan in 2004 and Hurricane Ida in 2021. 

Tornadoes associated with decaying tropical systems are typically weaker than those that develop within supercell thunderstorms. Tornadic thunderstorms are exceedingly rare in Washington, D.C., but do occasionally occur.

The last tornadoes in the nation’s capital occurred on July 1, 2021. An EF-1 tornado touched down in Arlington County, Virginia, and crossed the Potomac River into the nation’s capital where minor damage was observed. This tornado dissipated near 16^th Street and Independence Avenue in Northwest shortly after 9:00 p.m. Another tornado, an EF-0, touched down a short time later in Northeast D.C. where tree damage was reported. 

Prior to that, the last tornado outbreak in the nation’s capital was on April 6, 2017 when two EF-0 tornadoes were confirmed by NOAA. Although minor damage was observed, there were no fatalities. 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 25 years. On April 28, 2002, an exceptionally rare F4 tornado occurred in Charles County. This tornado had a track that spanned nearly 70 miles. It reached 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. 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. Two sisters who were students at the University of Maryland tragically 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 as high as 210 mph.

According to NOAA data, Maryland averages 10 tornadoes annually, while Virginia sees 18.  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.