No. 3: Spring Tornado Outbreak

The drama of the year’s extreme weather began to truly show itself in the spring, as the nation experienced extremes on many climate levels. While record drought and fires were still gripping the Southwest, flooding and record rainfall were hitting the Midwest. The most severe weather of the month took its toll in the Southeast, as it was hit with an onslaught of tornadoes.

According to the National Oceanic and Atmospheric Administration (NOAA), April set the record as the most active tornado month in history with 753 tornadoes causing 364 fatalities. This new record shattered the previous of 542 held by May 2003.  Some have connected these outbreaks with La Nina, drawing comparisons to a devastating outbreak under similar conditions in 1974.  May and June are normally the busiest months of tornado season, but this year the season grew deadly a month earlier.

From April 14 to April 16, 178 tornadoes were recorded in 16 states, with a death toll of 43. Not only was this supercell of tornadoes out of the ordinary, it also caused major events in places outside the usual “Tornado Alley.” North Carolina, which averages 19 tornadoes a year, had 25 in just one weekend. The state also suffered the highest death toll (22) from this particular outbreak. This midmonth outbreak of tornadoes set a new record for number of tornadoes in the month of April, only to be broken by an even bigger outbreak two weeks later.

World record

The second outbreak of tornadoes hit the Southeast from April 24 to April 29. This five-day outbreak is now the greatest in recorded world history. It had double the number of tornadoes (353 in 21 states) than the previous record, which was set just two weeks earlier, and killed 321 people. On April 27 alone, there were 188 confirmed tornadoes, including the devastating EF-4 that hit Tuscaloosa — one of the most damaging of all time.

Tornadoes are caused by cold air colliding with warm moist air over the jet stream. This spring’s unusually strong jet stream aided the updrafts in the atmosphere that caused such an abundance of tornadoes. According to Jeff Masters of the Weather Underground, climate change is expected to cause a weakening of the jet stream in coming years, so there is no telling if this type of extreme weather is expected to increase in the near future. A perfect storm of circumstances can cause these events to increase in any given year, though the warming, increasingly wet atmosphere can lead them to become more dangerous in the future.

Ongoing relief efforts:

Becky Uline is an editor and musician living in San Francisco, where she enjoys digging into Yahoo! data as a sidekick to trend-finding sleuth Vera H-C Chan. Most of her writing is of the musical variety for her band, the Northerlies.