Not that anyone’s complaining, but Iowa isn’t seeing its usual share of tornadoes this year. Iowa had already recorded five tornadoes by this date last year, all five of which came on the same day, March 23rd, 2009. State climatologist Harry Hillaker says, “Two years ago, 2008, which was a very active tornado year, we’d already had 11 by this date, and in that case, all of those also came on just one day, on April the 10th.”
Hillaker says Iowa’s tornado season usually begins in late March or early April and often peaks around early-to-mid-May. “So far in 2010, we’ve had a grand total of zero tornadoes reported in the state,” Hillaker says. “We did have some very severe wind damage, particularly in the Grinnell area roughly a week ago but that was from straight line winds rather than tornadoes. Typically, by this time of year, normally (there are) about four tornadoes in Iowa.”
Some experts attribute the lower tornado numbers, in Iowa and across the region, to an unusual weather pattern that’s keeping the Midwest slightly warmer than usual and the South a bit cooler. There have only been about 75 tornadoes reported nationwide this year. That compares to 270 on this date a year ago and 470 two years ago. Hillaker says Iowa’s seen an about-face in its tornado numbers over the past two years.
“Overall, say for the whole season, Iowa in recent years is averaging about 48 per year,” Hillaker says. “Last year being a very quiet year, we only had 25 for the entire year and 105 in 2008, which of course was a very busy year for severe weather.”
That year’s major weather events included two killer tornadoes that hit Parkersburg in northeast Iowa and the Little Sioux Scout Ranch in western Iowa’s Harrison County, in addition to the record floods which washed over much of the state.