An unprecedented mid-December severe weather outbreak will take place Wednesday across Iowa, Minnesota and Wisconsin, where widespread damaging winds and "at least a few tornadoes" are likely, according to the National Weather Service.
The messaging from the Storm Prediction Center is alarming, noting that damaging winds could reach 100 mph and strong tornadoes are possible:
"Widespread severe wind gusts of 60-75 mph along with at least a few tornadoes are likely from late afternoon through this evening across the Mid-Missouri Valley to the Upper Mississippi Valley. Embedded gusts of 80-100 mph and a nocturnal strong tornado or two are also possible, particularly across western to northern Iowa and southeast Minnesota."
The SPC has placed a sizable area of southeast Minnesota in a rare moderate risk (level 4 of 5) for severe storms. Tornadoes will be possible even as far north as the Twin Cities.
The tornado threat appears to be maximized from north-central Iowa into southeastern Minnesota and far western Wisconsin. It includes Albert Lea, Mankato, Rochester and Red Wing. The hatched area in the yellow zone below is where strong tornadoes are most likely to form, though the entire area can't rule out damaging twisters.
The primary severe threat will be damaging straight-line winds, which could reach 100 mph in the strongest bursts. Keep in mind that these storms will be moving at 60-70+ mph, so it won't be difficult for those stronger winds aloft to reach the ground in downbursts.
Here's a look at the 7 a.m. updated HRRR radar simulation. It shows an arcing line of supercells blasting through the risk area and reaching the Twin Cities between 7-10 p.m.
You can see heavy, wet snow and mixed precipitation falling in western and northern Minnesota along the backside of the low-pressure system. Snow could accumulate to a few inches in some areas, but perhaps the bigger concerns are the winds whipping the snow around and the extreme temperature drop that will lead to flash freezing overnight.
The high temp in the Twin Cities is forecast to reach 61 on Wednesday, then plummeting to an overnight low of 23. All of the rain that falls could wind up rapidly freezing, causing dangerous travel conditions.
Overall, the messaging from the NWS Twin Cities sums up today's insane weather like this: "TODAY'S VOLATILE DAY OF WEATHER HAS NOT BEEN SEEN BEFORE IN MID-DECEMBER..."
We'll have updates throughout the day from meteorologist Sven Sundgaard and Novak Weather. Check back for more and stay weather aware today.