Along with the threat for severe storms comes the chance for flash floods from heavy rainfall, the Weather Service said. "Ample moisture and instability (are) also present to support excessive rainfall rates, making flash flooding a concern in the Middle Mississippi and Ohio/Tennessee River Valleys," Mullinax said.
Meanwhile, an "enormous" winter storm will mark the end of 2021 and the beginning of 2022, as it produces accumulating and travel-halting snowfall in at least 18 states from the Southwest to the Midwest, AccuWeather said. "This will be a massive storm in terms of the area of coverage ... 3-8 inches of snow in the central United States that includes Chicago and many other hubs," AccuWeather meteorologist Bernie Rayno said.