UPDATE, SUN 10 PM: The last storm cell is moving out of the area.
More than 4000 are without power due to strong winds.
Look for a few scattered showers Monday, but the severe weather threat is over for now.
UPDATE, SUN 8:30 PM: Authorities in the Metro East community of Fairview Heights say a tornado touched down there Sunday evening.
A dispatcher at the Fairview Heights police department reports at least two businesses sustained damage, and authorities continue to canvas the community to determine what other damage was inflicted on the town.
High winds also have caused damage in Springfield and several nearby towns.
According to Sangamon County Sheriff Neil Williamson, a trailer park on Springfield's northeast side has sustained damage from the strong winds.
Damage has also been reported in the Christian County community of Taylorville, located southeast of Springfield.
Chatham Police Chief Roy Barnett says strong winds that swept through the town ripped shingles off buildings, but caused little other damage.
There have been no reports of injuries.
Copyright 2006 by The Associated Press. All Rights Reserved.
UPDATE, SUN, 8 PM: Most of the Tri-State is under a thunderstorm warning, with parts under a tornado watch.
These storms are capable of producing strong winds and hail.
Newswatch has received numerous reports of damage. We have crews on the scene and will continue to update you with the latest.
UPDATE, SUN, 6:30 PM: The entire Tri-State is under a tornado watch until 1 a.m. Monday.
A strong cold front is sweeping through the midwest Sunday evening, forming a severe line of thunderstorms ahead of it.
Large hail, winds in excess of 70 miles an hour and isolated tornadoes are possible. Heavy rains could also cause flooding on roads, so be careful if you are traveling Sunday evening.
PREVIOUSLY: The Tri-State is under a slight risk for severe weather Sunday.
A strong, low pressure system is making its way towards the Tri-State.
Plenty of moisture and strong winds aloft and at the surface will provide the ingredients for storms that could produce damaging winds and isolated tornadoes.