Seasons First Accumulating Snowfall Shortly Underway
A taste of the winter season is upon us once again as the Northland braces for yet another risk for snowfall but this time, with accumulations likely. There are winter storm watches in effect for Koochiching, St. Louis, Lake, and Cook Counties until 7 AM. An abnormally moist and powerful clipper from Canada will move into parts of North Central and Northeast Minnesota starting overnight. It will start off as rain with the area under the warm sector of the storm, but then transition to snow.
Starting tonight, clouds will be advancing in ahead of the precipitation band. Rain showers will develop later during the overnight with winds out of the east and southeast at 5 to 15 mph. Temperatures will remain in the mid and upper 30s so any precipitation will be in the form of rain. The cold air will start to sink south from Canada as the sun rises over the horizon tomorrow. The first areas to see the transition from rain to snow will be along the Borderlands late in the morning into the early afternoon. Temperatures will be initially in the mid 30s so some of the snow won’t accumulate rapidly, likely to begin on elevated surfaces.
Slowly but surely, with which the rate of which snow will be falling, it will cool off the ground temperature to freezing and snow will begin to accumulate. There will be some melting of snow in the process of accumulation so snowfall totals that are being projected on raw model outputs are too high for the likely scenario. Snowfall will be occurring from Bigfork to North of Ely by 4 pm. By 8 pm, snow will move from a line from Aitkin to Hibbing to Grand Marais with temperatures along the freezing mark. By 2 am Friday, the rain snow line will hug along the North Shore and along the Wisconsin and Minnesota state line. Temperatures win Minnesota will be in the upper 20s and lower 30s. Upper 30s and lower 40s will be in Northwest Wisconsin where rain will be falling.
Rain and snow will mix along the lakeshore in Minnesota with little to no accumulation because of very warm lake water temperatures. Snow showers will end by Friday afternoon along the Minnesota shore. Rain will transition to snow in Northwest Wisconsin in the afternoon after 2 pm. The lakeside areas will see rain however with the east and northeast flow. As this storm system begins to lift out of the Northland Friday evening, cooler air will move in overnight with temperatures dipping into the mid and lower 20s. the North and northwest wind flow behind the departing storm will crank up the lake effect snow machine from Ashland to Gogebic County with the potential of seeing snowfall totals inland of lake superior as much as a half foot.
To Recap, snowfall will begin overnight along the Canadian border and will persist throughout at least the first half of the day tomorrow. The snowfall will then move farther southeast as the day goes on with cold air filling into the area. Snowfall amounts in Northeast Minnesota will be the highest along the Borderland with 3 to as much as 7 inches possible. Farther south, A large area of 1-3 inches looks likely, especially north of a line from Aitkin to Duluth.
Locations along the immediate lakeshore from the Twin Ports to Grand Portage will see little to no snowfall accumulation based on the lake water temperatures being in the lower to mid 50s. In Northwest Wisconsin. Most of the snow will be occurring during the day on Friday where temperatures will be above freezing. Snowfall accumulations will be hard to come by. However east of Ashland along the south shore snow melt, the strong north and northwest flow will create lake effect snow showers that will accumulate to near or higher than a half foot from Ashland to Gogebic County. Snowfall accumulations along the lakeshore will not occur because of 50 degree water temperatures warming the air as it travels across the lake to the shoreline.
-Chief Meteorologist Gino Recchia