Severe thunderstorms will rumble across a large swath of the United States on Monday into the evening, with the most destructive potential in the Upper Midwest.
On Monday, 36 million people are under the risk of severe storms from northern Minnesota to southwest Texas, where strong tornadoes, hail up to 2 inches in diameter and damaging straight-line winds are possible.
There will be two rounds of storms Monday: one will roll through Minnesota by noon, with hail as the primary risk, and a second will erupt by the afternoon and continue through the evening.
Several destructive storms are likely to pummel Minnesota, Wisconsin and northern Iowa. Further to the south and west, storms will be more isolated.
Minneapolis, Rochester, Minnesota; La Crosse, Wisconsin, and Des Moines, Iowa, are the cities with the most significant tornado threat.
Officials in the Twin Cities are closely monitoring the weather system. Ramsey County Emergency Management and Homeland Security Director Judd Freed told NBC affiliate KARE of Minneapolis that locals should have an emergency plan, have electronics fully charged and heed outdoor warning sirens.
“If you do hear those sirens tomorrow, stop what you’re doing if you’re outside — if you’re out in the park or wherever — start looking for some shelter and find out what’s going on,” Freed said.
Over the weekend, at least one person died in flash flooding that hit Oklahoma. The Lawton Police Department said Saturday the death came after a person drove into standing water.
Heavy rain in the region led to inundated roads, evacuation notices and water rescues.
The storm system behind Monday’s outbreak will continue east into Tuesday, with 46 million people at risk for severe storms from northern Vermont to western Texas.
Across this area, there will be two regions with slightly higher chances of damaging storms: first, across west Texas into central Oklahoma, and second, across the Ohio Valley into the interior Northeast.
Tuesday’s main threat is large hail. On Wednesday, the next storm system will enter the Plains, leaving 8 million people at risk for storms capable of all hazards across northern Texas.
Flash flooding will also be a concern from Tuesday into Wednesday, following repeated storms that are expected to dump 2 to 4 inches of rain from northern Texas to southern Missouri, with locally higher amounts of over five inches.
Cities that could see flooding Tuesday include Oklahoma City, Tulsa, Oklahoma, and Wichita Falls, Texas. Cities that could experience flooding Wednesday include Texarkana, Texas, and Fayetteville, Arkansas.
