Significant Severe Weather ?

Tornado Averages for the United States   (Source: NOAA)

The United States averages more tornadoes than any other country in the world.  That’s because of our unique geography that creates favorable conditions during the spring and summer months.  “Tornado Alley” covers a large portion of the central U.S. from Texas to South Dakota.  Land-falling tropical systems along the Gulf Coast or the East Coast often spawn tornadoes during the summer and fall months.

In addition to tornadoes, severe weather also includes damaging wind gusts of at least 58 mph and hail of 1” in diameter or greater.  March typically sees an uptick in the number and frequency of severe thunderstorms, but isn’t as busy as April, May or June.  That’s why meteorologists and local governments promote severe weather awareness in March to ensure the general public is informed and aware of the associated risks. 

The state of Virginia declared this week (March 12 – 16) “Tornado Preparedness Day and Drill.”  Meanwhile, Maryland declared March 19 – 25 to be “Severe Weather Awareness Week.”  There have been several notable severe weather outbreaks in March, both nationally and locally in the DC Metro Area.  For example, two weak tornadoes developed in northern Virginia on March 10, 2011, as part of a larger local severe weather outbreak.  And on March 4, 2008, much of the eastern United States from Georgia to Rhode Island experienced severe weather.

Two of the largest March severe weather outbreaks in the United States occurred in the last 25 years.  This week’s 25^th anniversary of the “Superstorm of 1993” has gotten a lot of attention.  That storm brought record snowfall from Alabama to New England.  However, it wasn’t just snow as it also brought a large amount of severe weather.  A damaging line of thunderstorms spawned 11 confirmed tornadoes and more than 15 reported wind gusts of 70 mph/+.

More recently, another March severe weather outbreak covered an even larger geographic area.  On March 2, 2012, there were nearly 700 combined reports of severe weather from Texas to Ohio with 132 confirmed tornadoes.  Although no severe weather occurred in the immediate DC Metro Area during that outbreak, it remains one of the largest March severe weather outbreaks on record.