Despite the calendar reading April, more snow is ahead for much of the Northern Tier between Sunday and Tuesday. Some places may even receive a foot of snow by the time the snow comes to an end in the Upper Midwest.
This Sunday, the snow activity will be confined to the Northwest as the storm moves into the region. Snow is forecast to fall in the Cascades as well as much of the northern Rocky Mountains. Meanwhile, rain showers will fall in the valleys of the Northwest and along the Washington and Oregon coasts.
Then overnight Sunday, the snow will become more widespread, impacting the higher elevations of Washington, Oregon, Idaho, Montana, and Wyoming. The lower elevations will deal with a few light rain showers.
Now on Monday, a new, powerful low pressure will begin to develop on the leeward side of the Rocky Mountains in Colorado. These types of storms are very common in the colder months where air sinks and compresses east of the Rockies, thus forming a new low pressure system. This storm will bring snow on Monday to similar areas in the Northwest that received snow Sunday night as well as to portions of the Dakotas near the border, central Minnesota, and central Wisconsin.
Our storm will really begin to crank as it strengthens to a sub-995 millibar low Monday night. A widespread light to moderate snow is expected from eastern Montana and Wyoming through much of the Dakotas, northern Nebraska, much of Minnesota, northern Wisconsin, the Upper Peninsula of Michigan, and northern Lower Michigan. Snow may also work into northern parts of Iowa. Meanwhile back in the Northwest, all of the unsettled weather activity will come to an end.
On Tuesday, our storm will continue to strengthen, which will fuel a line of strong to severe storms from the Ohio Valley through the southeast Texas coast. In terms of the snow, a light to moderate snow is expected from South Dakota and eastern Nebraska through northern and western Iowa, southern Minnesota, northern and central Wisconsin, the Upper Peninsula of Michigan, and northern Lower Michigan. Precipitation may extend into the interior Northeast by this time, so some snow is possible across portions of Upstate New York and northern New England.
Overnight Tuesday, snow will exit the Northern Plains while persisting at least for the first half of Tuesday night in eastern portions of Minnesota and Iowa, most of Wisconsin, the Upper Peninsula of Michigan, and northern Lower Michigan. Some light snow may even work into the northwestern suburbs of Chicago. A brief period of snow may also affect northern Maine while the rest of the Northeast deals with rain due to temperatures in the upper 30s to 40s and 50s.
As we get into Wednesday, the snow portion of this storm will wind down. A light snow on the backside of this storm is possible, however, across much of the Great Lakes region. By the end of the day, rain may even changeover to snow across portions of New York and Pennsylvania and eventually northern New England Wednesday night.