The weather service issued a flash flood watch from Arkansas northeastward through parts of Missouri, Illinois, Indiana and Ohio, with up to 4 inches of rain projected. With falling temperatures, some of that could be freezing rain by Saturday night in the St. Louis area, weather service meteorologist Jon Carney said.
In Indiana, the National Weather Service posted flood warnings along southern and central Indiana streams and predicted the highest flood crests along the East Fork of the White River since April 2011.
While the Midwest and Plains were preparing for ice and snow, residents down South were concerned about tornadoes, which forecasters said were possible this weekend even though they are uncommon this time of year. The area most threatened stretched from central and northeastern Texas through Louisiana, Mississippi, Arkansas and southeast Missouri, where 80 mph wind gusts and flash flooding were possible.
Tom Kines, an AccuWeather meteorologist, said a northern cold front clashing with warm, humid air from the South is causing the unsettled weather.
"I think there's a high likelihood there will be severe storms with hail and damaging wind" in parts of the South, Kines said. "Whether or not there's tornadoes, that's tough to say, but I will say the conditions are right."
Weekend temperatures could surpass 70 degrees in Nashville this weekend and approach that in New York City as well, Kines said. But by Sunday night, the storm will be hammering the Northeast, where residents could be treated to a rare winter thunderstorm.
If there is a silver lining, it's that Christmas happens mid-week this year, AAA spokeswoman Heather Hunter said.
"When a holiday falls on a Wednesday it gives travelers more flexibility of either leaving the weekend before, or traveling right before the holiday and extending the trip through the following weekend," Hunter said.
Associated Press writers Shelley Adler in Washington, D.C.; Kelly P. Kissel in Little Rock, Ark.; David Sharp in Portland, Maine; and Dinesh Ramde in Milwaukee contributed to this report.
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