ShareThisAs the spring storm season begins, the nation's largest private weather forecasting company says Tornado Alley may move east this year.
This season, AccuWeather.com meteorologists expect tornado activity will increase farther east into the Midwest instead of the traditional spring tornado swath, which consists of parts of Texas, Oklahoma, Kansas, Nebraska and South Dakota.
"Tornado season usually begins in March, but this year, there has been a lack of tornadoes. A total of 64 tornadoes have occurred as of March 29. On average, 225 tornadoes occur by this date," AccuWeather.com said in a release to media.
The company attributes the low number of twisters to a cooler-than-normal Gulf of Mexico, a jet stream displaced farther south than normal due to El Nino, and persistent cool weather in the Plains and South.
"The Midwest appears particularly primed for additional tornado outbreaks this year rather than the typical Tornado Alley states because of the predicted storm track and the proximity of gulf moisture should be present by late April, the company said.
AccuWeather.com analyzed tornado reports dating back to 1950 from the Storm Prediction Center during April, May and June of 1958, 1966, 1978, 1988, 1993, 1995 and 2003, the most recent years categorized as El Nino events.
"Two patterns emerged from this information: many states had fewer tornadoes reported early in severe weather season than normal, and then higher totals emerged in the following months for some states," the company's release said. "In April, the southern tier of states, including Oklahoma, Texas, Louisiana, Mississippi, Alabama and Florida, reported an increased number of tornadoes than they typically see. Meanwhile, nearly all states to the north of that line saw fewer twisters in El Nino years."
But AccuWeather.com said severe weather often returned "with a vengeance" in the states lining the Mississippi River and many Southern states in May.
The National Weather Service's Climate Prediction Center shies away from long-term predictions on severe storms or tornadoes, preferring to make seasonal forecasts based solely on precipitation and temperature. Its latest assessment is that North Texas and southern Oklahoma will see above normal precipitation through April and a slightly cooler spring than normal with average rainfall.
"I don't put a lot of stock into it," said Harold Brooks, of seasonal or long-term predictions of severe thunderstorms or tornadoes. Brooks is a researcher with the National Severe Storms Laboratory in Norman, Okla.
He said there is little evidence of El Nino years having a significant effect on severe or tornadic weather in the U.S.
"It's very slight -- a few percentage points at most," he said.
(Distributed by Scripps Howard News Service, www.scrippsnews.com.)
