Lightning and heavy rain were part of severe weather that swept through Decatur on Monday night. UPDATE 9:30 P.M. A severe storm system swept across Central Illinois on Monday evening, sending several counties into shelter mode. The National Weather Service at Lincoln issued tornado warnings for several counties, including Macon, throughout the evening. It reported that a confirmed tornado was spotted at 6:15 p.m. near Mechanicsburg, 6:35 p.m. over Niantic and 6:42 p.m. near Harristown. The extent of damage across the region was not immediately clear Monday night. A severe thunderstorm watch expired at 9 p.m. Isolated thunderstorms are possible on Tuesday, Thursday afternoon and again from Saturday afternoon through Sunday, the weather service said. The risk of severe storms is low during this time, though lightning hazards exist.