Thursday, March 7, 2019

Deadly March Weather


The severe weather outbreak this past Sunday, March 3 was the deadliest in the United States since 2013.  Nearly three dozen tornadoes have already been confirmed across the southeastern United States from Alabama to South Carolina.  Sunday’s deadliest tornado initially touched down in Macon County, Alabama and grew into a rare EF-4 tornado with winds of 170 mph.  It caused 23 fatalities in the small town of Beauregard, Alabama about 60 miles east of Birmingham.

Sunday’s tornado in Beauregard also became Alabama’s deadliest March tornado since the Palm Sunday outbreak on March 27, 1994.  That’s when at least 22 fatalities were reported in an F4 tornado that passed through the small town of Goshen, Alabama.  It’s important to distinguish between the EF-4 that occurred this past Sunday and the F4 that was reported 25 years ago.  Back in the 1970s, tornado intensity was measured on the Fujita Scale that went from a F0 tornado with wind speeds of 40 mph – 72 mph to an F5 tornado (261 mph – 318 mph).  However, in 2007 the revised “Enhanced Fujita Scale” ranks a minimal tornado an EF-0 with wind speeds of 65 mph – 85 mph.  An EF-5 tornado has wind speeds of 200 mph or greater.

In addition to the more than 30 confirmed tornadoes that occurred during the March 3, 2019 severe weather outbreak, there were numerous reports of severe wind gusts (58 mph/+) and severe hail (1”/+ in diameter).  By comparison, the largest March severe weather outbreak in all of last year occurred on March 19.  On that day, there were 28 confirmed tornadoes in the southeastern United States without any fatalities.

Due to its unique geography, the United States sees more tornadoes in an average year than any other country in the world.  According to the National Centers for Environmental Information, the United States averages 1,253 tornadoes per year for the period from 1991-2010.  The month of March is the sixth busiest month of the year for tornadoes, with an annual average of 80.  The months of April through August all have a higher average number of tornadoes than March.  

March is typically when the weather across the central and southern United States starts to warm up and become more spring-like.  Consequently, the average number of tornadoes increases dramatically from only 29 in February to the March average of 80.  Following the fall and winter months when severe weather and tornadoes are few and far between, the uptick in March is noteworthy.  That’s why it’s vital to listen to the latest weather forecasts from your favorite local meteorologists.

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