Dangerous July Severe Weather Outbreaks

 

Photo Credit: Robin Beal

Although less common than in April, May or June, the D.C. Metro Area has seen its fair share of severe weather in July.  Thunderstorms have been a fairly regular occurrence so far this month, which has been especially rainy.  Given the severe weather potential the next few days, here are a few memorable July outbreaks in recent years.

2022: The D.C. Metro Area had a very busy severe weather day on July 12.  Following a typical July afternoon with highs in the 90s and dewpoints in the low 70s coupled with a high degree of atmospheric instability, there were multiple severe wind and hail reports between 4:00 p.m. and 9:00 p.m.  This outbreak came a week after another outbreak that included two tornadoes.  One tornado touched down in Bowie, Maryland and another occurred in Anne Arundel County, Maryland.  Fortunately, power outages were minimal and no fatalities were reported.

2021: Two confirmed tornadoes occurred within D.C. city limits on July 1.  An EF-0 with winds of approximately 80 mph occurred near the U.S. Capital.  A second tornado developed in Arlington and tracked across the Potomac into D.C.  It was an EF-1 with peak winds of 90 mph during its 4.4-mile path.  In addition to the tornadoes, what made this severe weather memorable is how two separate rounds occurred.  The first round of severe weather was during the peak heat of the afternoon and the second occurred between 9:00 p.m. and 10:00 p.m. when the tornadoes developed. 

2017:  Several rounds of thunderstorms brought severe weather and flash flooding to parts of the D.C. Metro Area from July 22 - 24.  The most significant occurred in Queen Anne’s County in Maryland on July 23.  An EF-2 tornado was on the ground from 1:29 am to 1:33 am, with peak winds of 125 mph.  Although the tornado caused appreciable damage to the towns of Bay City and Stephenville, Maryland, no fatalities occurred.  A total of 2.37” of rain occurred at National Airport during this 3-day span.

2010:  A significant heat wave was capped off on July 25 with highs near 100° and an unstable atmosphere.  That’s when a squall line developed west of town and came through the Nation’s Capital with multiple severe wind gusts.  These storms produced a slew of downed trees and power lines and resulted in widespread power outages, especially in densely populated Montgomery County, Maryland.

A thunderstorm becomes “severe” when it contains one or more of the following: wind gusts of at least 58 mph, hail 1” in diameter or greater, or a tornado.  While heavy rain and lightning don’t make a thunderstorm “severe” per se, all thunderstorms are potentially dangerous and should be taken seriously.