April Tornado Outbreak One for the Record Books
by Jason Berry/ Lead Meteorologist
Update: May 7, 8:41pm ET
April was a record setting month for tornadoes across the U.S. Preliminary estimates by the National Weather Service suggest more than 600 tornadoes occurred last month, smashing the previous record of 542 for a single month set in May 2003.
Of those, 211 occurred from 8:00 a.m. EDT April 27 to 8:00 a.m. EDT April 28. 344+ people were killed in the south, including 65 by an EF-4* tornado, with winds topping 166 mph in Tuscaloosa and Birmingham. This is the second deadliest two-day spree of tornadoes since April 5-6, 1936, when 454 people were killed, mostly in Tupelo, Mississippi and Gainesville, Georgia.
This is also the second deadliest single day for tornadoes, since the March 18, 1925 outbreak that killed 747 people across seven states. Of those, 695 were killed along a 219 mile continuous path in Missouri, Illinois and Indiana. To-date, the Tri-State tornado remains the single deadliest tornado on record in the U.S. and the longest ever in the world.
The average number of tornadoes for the month of April this past decade was 161. The previous record for the month was 267 set in 1974. Of those, 148 occurred during a 24-hour span between April 3 and 4 during the historic "Super Outbreak".
YouTube video from jason835a showing the raw power of the tornado that struck Tuscaloosa, Alabama
So, why so many tornadoes? Some suggest La Niņa. Unlike El Niņo, La Niņa causes cooler than normal sea surface temperatures in the equatorial and eastern Pacific. This year's La Niņa was the strongest in 35 years, and has been linked to lingering winter-like weather across the Pacific Northwest, northern Rockies and upper Midwest. Thunderstorms thrive along sharp boundaries between warm and cold air, a trend more often observed in May during peak tornado season in the U.S. Read More about La Niņa
Although no clear climatological evidence exists to support such a claim, many analysts continue to blame La Niņa for the year's increased severe weather. However, April barely ranked in the top 25 percentile in days with active tornadoes, with 20. According to the National Weather Service, the record number of days with tornadic activity for April is 23, having only occurred 3 times to-date.
Numerous violent tornadoes like this one (above) touch downed across the south, some on the ground for over 200 miles. Pictures of the aftermath (below) show widespread destruction across Alabama and surrounding states. Courtesey: NOAA/ National Weather Service
