As a new winter storm begins to move into the West, which already dumped rain and snow throughout portions of the region, a surface low will also develop on the leeward side of the Colorado Rockies. This will eventually become a major winter storm for portions of the Central Plains and Midwest. Blizzard Warnings are in effect from northeastern Colorado through northwestern Kansas, much of Nebraska, extreme-southeastern South Dakota, extreme-northwestern Iowa, and portions of southern Minnesota due to the heavy snow and strong winds that will lower visibility. We break down the timing and specific impacts with this storm in this article.
A Colorado low will develop early Sunday morning, therefore leading to the start of impacts from the Rockies through the Great Lakes. This low will begin with pressures at around 1005 mb (millibars), but will drop to around 995 mb by the time it reaches the Great Lakes on Tuesday. So starting Saturday night as the storm develops, snow will break out and will fall from the Rockies with a light snow already sneaking into portions of Nebraska and South Dakota. During the day on Sunday, a light to moderate snow will fall across much of Colorado, Nebraska, southern North Dakota, and western Kansas. Meanwhile to the south and east, rain and thunderstorms will form from Iowa and the southeastern corner of Nebraska southward to the Gulf Coast. The biggest city that will be impacted with this snow on Sunday will be Denver. Several inches will fall, so get ready for a messy Monday morning commute back to work.
Then overnight Sunday, snowfall intensities and winds will begin to ramp up as the storm becomes stronger. As of now, the axis of heaviest snow looks to span from southwestern Nebraska through northern Iowa. Otherwise, a light snow or snow showers are forecast from western Colorado early through much of the Central Plains and into northern Iowa, southern Minnesota, and central Wisconsin.
Now on Monday, the worst of the storm will work into the Upper Midwest as pressures at the center of the low continue to drop. Winds may gust as high as 40 to 50 mph just north and west of the center of the low. That includes northwestern Iowa, eastern Nebraska, and southern Minnesota. In terms of where the snow will fall, it will span from eastern Nebraska and Kansas through the western Great Lakes, including northern Wisconsin and Michigan. Even a few snow showers may sneak into Upstate New York and northern New England by the end of the day Monday. The axis of the heaviest snow will likely be found from northwestern Iowa through southern Minnesota (just south of the Twin Cities) and into northern Wisconsin and Michigan. As the center of the low moves through Iowa, we’re actually going to see the rain and thunderstorms transition to snow by the evening for Iowa and Missouri.
By Monday night, the storm will quickly zoom towards the Great Lakes region. A light snow now will continue in the Upper Midwest, including southern Minnesota and much of Iowa and Missouri while snow showers move into Illinois and Indiana. Also a moderate to heavy snow early from central or northern Wisconsin into the Upper Peninsula of Michigan will transition to lingering snow showers by the end of Monday night.
On Tuesday, snow showers are possible on the backside of the low across the Great Lakes region as well as in the Ohio Valley, although little to no snowfall accumulation is expected. In the Northeast, Monday night and/or Tuesday, snow and freezing rain is possible from Upstate New York through northern New England. Otherwise it will be a rain story for the rest of this region.
By Tuesday night into Wednesday, the storm will clear out of the Northeast, but may leave lingering snow showers across the interior of the region.
Below is our snowfall forecast based on our current thoughts (updated 4:45PM Saturday):