Tornado watches in Alexander, Union, Johnson and Pulaski counties were accompanied by strong winds and thunderstorms throughout Southern Illinois on Tuesday, but no damage was reported.

Kevin Smith, meteorologist with the National Weather Service, said strong winds and possible hail were most likely, but with thunderstorms accompanied by strong winds, isolated tornadoes are always a possibility.

Sheriffs' offices in Alexander, Union, Johnson and Pulaski counties said they did not receive any reports of damages or injuries in the afternoon. The biggest problem was water buildup, they added.

No known damages were reported in neighboring counties, including Franklin and Williamson.

Lee Doughty, an air traffic controller at Williamson County Airport, said the weather was "out of the ordinary," but it wasn't affecting flights.

"The weather hasn't been stopping our flying," he said. "The planes like small family planes that fly without instruments, they fly by sight. They don't fly on days like this. It's not a good day to fly."

Smith said the unusually warm weather "could spell trouble for a potential for severe weather."

"We just have warm, moist and unstable air," Smith said.

Smith explained that unstable, warm air from the Gulf of Mexico has mixed with cold air and strong winds to create the risk of the storms. Smith said tornadoes usually form in spring, but occurrences in winter are not impossible. Two F-3 tornadoes struck Owensboro, Ky., in January 2000, causing about $70 million in damages.

"Severe weather can happen any month of the year," Smith said.

He said there should be clearer skies today and some small showers in the next few days, but probably nothing as bad as Tuesday.

- Blackwell Thomas, Becky Malkovich and John Homan contributed to the story.

codell.rodriguez@thesouthern.com / 351-5804