Tornadoes didn’t spare Wichita or Kansas on April 14, but after that weekend they essentially took the rest of the year off.
Officials with the National Oceanic and Atmospheric Administration said 2012 is set to have the fewest tornadoes since official records began being kept more than a half-century ago.
Through November, 891 tornadoes had been reported in the United States, according to data provided by the National Oceanic and Atmospheric Administration’s National Severe Storms Laboratory in Norman, Okla. Only two other years since 1954 have logged fewer than 1,000 tornadoes through the same time period: 1987, which had 991; and 2002, with 957.
Greg Carbin, warning coordination meteorologist with NOAA’s Storm Prediction Center in Norman, calls them “the vanishing vortices of 2012.”
But don’t blame the Mayans.
Blame a dome of high pressure that settled over most of Tornado Alley shortly after the tornado outbreak of April 14 and stayed put.
“When there’s a ridge over the central U.S. for nine months, not much happens,” Harold Brooks, a research meteorologist at the severe storms laboratory.
There have been fewer tornadoes this year than there were even in the late ’80s, when tornado totals fell so low between 1985 and 1989 researchers were openly speculating that Tornado Alley could be destined for extinction.
Nobody’s predicting Tornado Alley’s demise now.
Not after a 2011 that saw the most tornadoes on record – 1,670 – and the most tornado deaths in more than 75 years.
It may seem impossible at first glance, Carbin said, but the tornado seasons of the past two years have a lot in common. Both were very active in the first four months, and then the seasons abruptly went silent.
May 2011 was among the quietest on record for tornadoes through the first two weeks of the month – until May 22, which saw an outbreak that included the EF-5 tornado which decimated the southern part of Joplin, killing more than 150 people.
Tornadoes tormented both Aprils: 2011 saw 758 tornadoes touch down in April, the most active tornado month on record, according to NOAA.
There were 206 tornadoes last April, almost all of them in the first half of the month. An outbreak on April 14 saw 24 tornadoes rake Kansas, including the EF-4 that struck Oaklawn and parts of south Wichita.
But after that weekend, tornado season “shut down,” Carbin said. “Tornadoes became almost non-existent, and any tornadoes we did have during this time were relatively insignificant.”
The dome of high pressure prevented the kind of environment in which tornadoes thrive: storm fronts colliding with warm, moist air moving north from the Gulf of Mexico.
“It gives us a little insight into the difficulty in predicting tornado events – especially activity in tornado seasons,” Carbin said.