Updated on: April 17, 2026 / 8:49 PM EDT / CBS News Add CBS News on Google The threat of strong tornadoes, large hail, damaging winds and flash flooding is returning to the central U.S. Friday evening into the start of the weekend, forecasters say.  Several twisters have touched down so far in Minnesota, Wisconsin and Illinois, including one in Lena, Illinois , that officials described as large and "extremely dangerous." The tornado caused extensive damage, according to local officials.  More than 51 million people are under the threat of severe weather from Texas to Wisconsin, and most of the storms will occur in the afternoon and evening hours. The forecast comes as communities are still cleaning up from tornadoes that struck earlier in the week.  Maps show severe weather, tornado forecast for Friday The Upper Mississippi Valley — spanning parts of Illinois, Iowa, Minnesota, Wisconsin — will have "the best chance for strong tornadoes," while parts of the central U.S.…