Even with the calendar flipping over to September, severe weather season continues in the northern tier of the nation. A stalled front over the Upper Midwest will bring a marginal risk for severe thunderstorms today (Tuesday), mainly focused in northern and central Iowa. The front will barely move on Wednesday as upper level energy sweeps across the Rockies. There is a marginal severe weather risk from Upper Midwest to the Front Range. The system starts to move eastward for the rest of the work week. With more instability in the atmosphere, there is a slight risk for severe storms from the western Great Lakes to the central Plains on Thursday, sweeping into the Northeast on Friday. For WeatherNation: Meteorologist Mace Michaels