Beware April’s Severe Weather

NOAA's Map of Severe Weather Reports (April 27, 2011)

This week is the anniversary of two significant severe weather outbreaks in the Mid-Atlantic Region.  Severe weather is defined as wind gusts of 58 mph or greater, hail 1” in diameter or greater, or a tornado.  Severe thunderstorms often have more than one of these things.

2011: There was a total of 2,708 severe weather reports including 492 tornadoes, 1322 severe wind gusts and 876 reports of large hail across the central and eastern United States from April 25 - 28.  The busiest day was April 27, when more than half (292) of the tornadoes occurred.  According to NOAA, four of these tornadoes reached EF-5 status with sustained winds of greater than 200 mph.  Sadly, a total of 231 weather related fatalities were reported on April 27.  

Also, from April 27-28, 2011, there were a total of 19 tornadoes in the DC Metro Region.  The strongest of these was an EF-2 in Rockingham and Shenandoah counties in Virginia.  Part of what made this outbreak so deadly was that a high percentage of the tornadoes occurred during the overnight hours when people weren’t awake to get the latest warnings.

2002: Longtime residents of the Mid-Atlantic Region will recall that Maryland’s strongest tornado on record occurred on April 28.  That’s when the town of La Plata in Charles County was decimated by an F4 tornado with wind speeds of 207-260 mph.  This tornado was on the ground for nearly 70 miles, including 24 miles in Charles County.  It reached its peak intensity while passing through the town of La Plata.  The town has been rebuilt in the years since then and is now vibrant and booming.   

The La Plata tornado was one of 18 tornadoes that developed on April 28 as part of a severe weather outbreak that saw a total of 389 severe weather reports, according to NOAA statistics.  Since, the original Fujita Scale was updated and became the “Enhanced Fujita” (or “EF) Scale in 2007, the La Plata F4 would now be ranked an EF-5 – as strong as tornadoes get.

A key lesson from these two severe weather outbreaks is how important preparedness is.  Knowing what weather watches and warnings mean and what to do in the event of a severe thunderstorm or tornado warning is issued for your area is vital.  The evolution of social media has improved dramatically since 2002 and so has smartphone technology.  Both social media and smartphones are critical for communicating vital weather information from meteorologists to the public.