Analysis from late Sunday afternoon.
Shown in degrees Celsius are the 850mb temperatures from 4 PM Sunday.
No changes to the winter weather headlines as of 4 PM Sunday
Winter storm warning in pink
Winter weather advisory in purple
Radar loop through 4:30 PM Sunday
Note: Snow that is showing up on radar in central Minnesota (Blue colors) isn’t reaching the ground quite yet as the atmosphere continues to slowly moisten up this evening which will allow the snow to reach the ground, eventually! Precipitation should continue to expand in coverage through Midnight.
Forecast maps through Monday afternoon
18z NAM-WRF model
Simulated radar forecast from 7 PM this evening to 1 PM Monday
Takeaway here is that we could see some areas of precipitation this evening with the heaviest precipitation expected overnight/early Monday morning, will then see precipitation end from W-E by early Monday afternoon.
Green and pink=Mixed precipitation
Here’s what I’ve come up with for snowfall amounts through Monday, not an easy forecast, but winter systems rarely are.
•I’ve lowered snow amounts for most areas except for the North Shore and Arrowhead where 8 to 14 inches of snow are possible by Monday afternoon (Yellow and Pink areas on map)
•For Duluth — 4 to 6 inches of snow on top of the hill, and 2 to 4 inches of snow below the hill in Duluth and also for the city of Superior.
•6 to 8 inches of snow around the Two Harbors area.
•An area of 4 to 6 inches of snow from International Falls east to Ely, south to Cotton.
•Lower snow totals farther west and south, generally in the 1 to 4 inch range.
•Expect some mixed precipitation with this system, especially along and south of Highway 2 in northeast Minnesota, and over much of northwest Wisconsin with a light glaze of ice possible.
Water vapor satellite loop from Sunday, January 6, 2019.
Our system for late tonight will have a lot of moisture to work with as Precipitable water values climb to 0.50 to around 0.75 inches across the Northland by later tonight.
Snow and mixed precipitation on the way!
What to expect
-Heavy snowfall rates of 1 to around 2 inches per hour along the North Shore of Lake Superior Monday morning. Gusty east to southeast winds combined with the falling snow will produce near whiteout conditions along the North Shore of Lake Superior Monday morning.
-This will be a wet heavy snow, especially across western-southern portions of the area including in Duluth and Superior.
-A mixture of wet snow, sleet and some rain across east-central Minnesota, most of northwest Wisconsin, possibly as far north as Duluth.
-Deteriorating road conditions due to the snow and mixed precipitation. Difficult travel conditions are expected from late tonight into Monday morning.
-Weather improves from west to east by Monday afternoon as precipitation ends while temperatures range from the lower to the upper 30s.
-A slow Monday morning commute is expected due to the snow and mixed precipitation, but the evening commute should be better for most of the Northland.
Concerns that I have with this system
1) One of the bigger ones is the fast movement of this system which could keep snow totals lower than what is forecast, but the exception to this would be along the North Shore of Lake Superior where very moist air and favorable E-SE winds off the lake will cause periods of heavy lake enhanced snowfall to occur Monday morning.
2) Temperatures and snowfall ratios. Temps will likely hold in the upper 20s or lower 30s through Monday morning which will result in a wetter snowfall compared to what we usually see around here. The mild temps will also lead to snow ratios being less than the usual 10:1, instead with this event we’re likely looking at snow ratios from around 5:1 to 9:1, the exception to this would be along the North Shore and over the Arrowhead where temps will be cooler, resulting in snow ratios from 10:1 to around 14:1.
For Duluth and Superior
…Winter Storm Warning in effect from 8 PM this evening to 11 AM Monday…
•Gusty east to southeast winds tonight into Monday morning (10 to 20 mph, gusts to 30 mph)
•Some light snow or freezing drizzle possible before midnight
•Snow becomes more widespread later this evening, most likely in the 9 PM to midnight time frame
•Snow overnight (after midnight) but some sleet could mix in at times
•Snow along with some possible sleet or drizzle tapers off Monday morning between 8-10 AM
•Total snowfall storm accumulations ranging from 4 to 6 inches in the north part of the city (on top of the hill) to 2 to 4 inches south part of the city (below the hill)