A very potent upper-level low centered over the Southwest will move toward the Upper Midwest and will end up there by Monday night while a surface low, also known as a Colorado Low, develops on the leeward side of the Colorado Rockies early-Sunday. This low will track to the Northern Plains on Monday, which is when it will peak in strength at about 994 millibars, before it drifts off to the south and east while weakening due to the interaction of it’s upper-level energy and another piece of energy diving southward from Canada. It is that interaction that may lead to another nor’easter for the Northeast on Wednesday.
So on Sunday, scattered rain showers and potentially thunderstorms will develop across the Northern Plains, affecting much of the Dakotas and into Minnesota, Iowa, and much of the Central and Southern Plains. There is the concern for some freezing rain in portions of North Dakota and Minnesota during the day Sunday due to freezing air at the surface. Watch for a glaze of ice which would make all surfaces slick in this region.
Now as we get into Sunday night, winds will begin to ramp up as our low pressure ejects into the Northern Plains. Widespread wind gusts of 35-50 mph can be expected following gusts of 30-40 mph during the daylight hours of Sunday. Starting at around midnight Sunday night, snow will break out first across northern Minnesota, where also some sleet and freezing rain are also possible, as well as across central South Dakota and Nebraska near the surface low. As the night progresses, we’ll see the wintry weather expand with a moderate to heavy snow expected from northern Nebraska, through most of the Dakotas, and into portions of northern Minnesota while rain falls to the south from the Gulf Coast through Iowa. Speaking of Iowa, eastern Iowa as well as eastern Minnesota should be on the lookout of freezing rain due to the eastern extent of the precipitation working into a thin layer of cold air at the ground. That icing threat will continue through about noon on Monday.
The Monday morning commute will be treacherous across a large region from the Dakotas through much of Minnesota as heavy snow continues to fall and blizzard conditions possibly occur over much of this area as winds gust up to 60 mph. In Minneapolis, snow and freezing rain can be expected for your commute into work, so it will be better to stay home because the day ahead will deliver even more worse conditions. That’s because heavy snow and blizzard conditions will move into all of Minnesota as well as into most of Wisconsin by the end of the day while continuing to fall across the Dakotas. Snow may even move into northern Illinois, including Chicago, for the evening. We’ll also see the center of the low drop to the south into the Omaha, Nebraska area, so that will bring snow into eastern Nebraska and western Iowa. Now as this storm occludes, allowing for drier air to reach the center of the low pressure, a dry slot is expected to develop, moving into central Iowa and southern Minnesota, especially southwestern Minnesota, during the afternoon. Depending on where that dry slot develops, that could make or break the forecast. That puts Minneapolis in play for either significant snowfall or minor snow. The model guidance shows a spread of between three and nine inches of snow possible for the city.
Then during the overnight hours of Monday, the peak of the storm will be over as snowfall rates decrease and drier air intrudes across the Northern Plains and Upper Midwest. Now even though the storm will begin to weaken, a light snow is still expected to fall at times across the Dakotas, Nebraska, Minnesota, Iowa, Wisconsin, northern Illinois, and the Upper Peninsula of Michigan. Blizzard conditions will also continue across portions of this region with wind gusts up to 35-45 mph in the Upper Midwest and as high as 60 mph in the Northern Plains.
On Tuesday, we’ll still be tracking this storm in a much weaker, less-organized state as Monday. That’s due to the upper-level low’s interaction to a piece of energy from Canada. There will also be drier air that works into the storm, making for spread out snow shower activity instead of a widespread, steady snow. Light snow can be expected at times on Tuesday across much of the Great Lakes region and into the Quad Cities region. Cities like Chicago, Milwaukee, Minneapolis, Des Moines, and Kansas City. Not much accumulation will be expected on Tuesday, although up to two inches may fall in some areas.