Not much has changed regarding the system for Saturday. Still looks cold enough for snow Saturday morning as precipitation moves into the Northland from the west and south, but a push of warmer air should cause the snow to change over to patchy rain and drizzle by Saturday afternoon, especially from east-central Minnesota into northwest Wisconsin, and also within about 10 miles of Lake Superior. Farther north the air mass should remain cold enough causing snow to be the main precipitation type thru the duration of this event.
Note: About the only concern I see is the fact the GFS model continues to show a lot less precipitation on Saturday, and is further south with its QPF compared to the other models today. Should the GFS verify, then there won’t be much snow at all on Saturday around International Falls, while snowfall amounts end up lower than the predicted 3-5 inches further south. Also of note is the latest RAP model (21z run) as it has shifted things much further south resulting in little to no snow from Bigfork and International Falls, east toward the Crane Lake area. So certainly a few things to watch this evening as new model data comes in.
My updated snowfall forecast for Saturday.
3 to 5 inches for Cass Lake, Walker, Remer, Hill City, Grand Rapids, Bigfork, Hibbing, Cotton, Cook, Ely and Isabella.
2 to 3 inches a little farther north and south of the 3-5 inch band.
1 to 2 inches for International Falls, Brainerd, Aitkin and Cloquet.
Less than an inch for Moose Lake, Solon Springs and Ashland.
Expected snowfall for Saturday zoomed in on the Twin Ports.
Generally 1 to 3 inches in higher elevation (on top of the hill) including the Hermantown and Proctor areas.
Less than an inch in lower elevation (below the hill)
Locations within about 10 miles of Lake Superior could see a period of snow Saturday morning (mainly before Noon) but temperatures should warm enough allowing snow to change over to drizzle or light rain by Saturday afternoon, and then we could switch back to a few flurries or snow showers near Lake Superior Saturday night as colder air returns.
Note: Locations farther inland up the hill in Duluth could remain cold enough for mostly snow through the day Saturday.
Snow develops around 3-6 AM Saturday around the Brainerd Lakes area, and in the 6-8 AM time frame farther north and east including in the Twin Ports and northwest Wisconsin.
Snow is expected to reach the Borderland and Arrowhead areas between 11 AM and 1 PM Saturday.
Note: A dry slot is forecast to move into southern portions of the Northland or generally along and south of Highway 2 in northeast Minnesota and all of northwest Wisconsin during the day Saturday, advancing ENE in the mid-morning to early afternoon time frame. As the dry slot moves over the aforementioned areas will see the snow switch over to light rain or drizzle.
Snow or rain ends from SW-NE Saturday night.
18z NAM 3km radar forecast valid from 1 AM Saturday to 1 AM Sunday.
Here’s the forecast track of Saturday’s low pressure system (yellow dashed lines on map)
A winter weather advisory is in effect from 5 AM Saturday to 1 AM Sunday for parts of northern and northeastern Minnesota including the cities of International Falls, Bigfork, Grand Rapids, Hibbing, Cook, Orr, Ely, Cotton, Two Harbors, Isabella, Silver Bay, Lutsen, Hovland and Grand Marais.
Snow on Saturday will lead to slippery road conditions. Slow down and use caution while traveling.
Winter Storm Severity Index valid for Saturday, October 17, 2020.
Check out how low the dew points are this afternoon, only in the 10s across most of the Northland, so there is a lot of dry air over the area which should result in snow being the main precipitation type Saturday morning.
If you want to escape the snow and chilly weather in northern Minnesota on Saturday then head south on I-35 where it will be quite a bit warmer on Saturday with 50s in the Twin Cities, and 60s farther south including around the Rochester area.
For the Northland, highs Saturday are forecast to range from the 30s to middle 40s (warmest around the Hayward Lakes area in northwest Wisconsin) Colder on Sunday with highs in the 30s.
System which will affect our area on Saturday is digging S-SE out of southwest Canada and into the Pacific northwest and Northern Rockies this afternoon.
Water vapor loop from Friday, October 16, 2020.
A cold air mass stretches from Canada south to the upper Midwest and Great Lakes today with 850mb temperatures as low as -10 to -14C, that is impressive for mid-October!
It doesn’t look like will be getting rid of this cold pattern anytime soon – Source region for our cold air extends from Alaska to the Arctic, south to northern and central Canada, and with a NW flow aloft all this cold air (although modified) heads south into our area.
Thanks for reading!