Parts of the Upper Midwest will have to brace for the potential of severe thunderstorms and flash flooding through the overnight hours. Thursday morning could continue to be wet and stormy as well. Here's the latest. A tornado watch has been issued until 1 a.m. central Thursday, July 12 for the potential of tornadoes and severe thunderstorms. A flash flood watch has been issued for parts of Minnesota and Wisconsin through early Thursday morning, July 12. A flash flood watch means there is potential for flash flooding in the dark green areas. A watch is issued when conditions may result in hazardous weather within the next several hours. When a warning is issued, that's when you want to take action! In this case, it means avoid driving through flooded roads and watch for areas of quickly-rising water. The risk of excessive rainfall overnight Wednesday into Thursday, July 11-12 Wednesday afternoon, the Weather Prediction Center added a 'moderate' risk of excessive rainfall for the greater Duluth, MN area. That means flooding is more likely in the dark shaded area. The simulated forecast showing rainfall (greens, yellows) and thunderstorms (oranges, reds) around 8 p.m. central Wednesday, July 11 A cold front will be sweeping east through the Upper Midwest, helping to lift thunderstorms up and grow them to mature, strong heights. The simulated forecast showing rainfall (greens, yellows) and thunderstorms (oranges, reds) around 12 a.m. central Thursday, July 12 The thunderstorms will likely transform into a line of repeated storms, raising that concern about flooding and flash flooding overnight. The simulated forecast showing rainfall (greens, yellows) and thunderstorms (oranges, reds) around 6 a.m. central Thursday, July 12 It may even be a wet and stormy morning commute for parts of the Upper Midwest Thursday. *Be especially careful of flooding overnight when the darkness makes it tougher to see high water!* For WeatherNation, Meteorologist Steve Glazier