CHICAGO (Reuters) - Forecasters put much of the nation's midsection on alert for rough weekend weather on Saturday as the first front of spring warmth was set to bring strong, volatile storms, including tornadoes, to the region.
Severe thunderstorms, large hail and damaging winds were likely over the next two days from Iowa in the west to the Carolinas in the east, said Jack Hales, lead forecaster at the National Storm Prediction Center in Norman, Oklahoma.
"These storms are not going to be messing around," Hales said.
"There already have been some very strong storms, producing damaging winds and large hail, in the lower Ohio Valley," he said. "And those are just going to continue and intensify, and spread down into Kentucky and eastern Tennessee, as the day goes on."
Further north and west, forecasters were keeping an eye on Iowa, southern Minnesota and Wisconsin, where Hales said there was a possibility of "quite a few tornadoes" Saturday and Sunday.
The peak U.S. tornado season runs from March through early July.
The culprit is a front of warm air surging northward across the country's midsection.
In Chicago, where the high temperature on Friday only reached 45 degrees, forecasters were predicting a high on Sunday of 88 degrees, the biggest 48-hour jump in April temperatures in more than three decades, according to Tom Skilling, WGN-TV's chief meteorologist.
But the dramatically warmer temperatures were expected to trigger strong winds and drenching downpours through Sunday.
"It's a typical springtime situation," Hales said. "We have a lot of heat and we have a have a lot of instability, so it results in some pretty organized severe thunderstorms."
(Reporting by James Kelleher, Editing by Ellen Wulfhorst)