Here’s my updated snowfall forecast valid thru Friday morning
*The entire Northland will get accumulating snow out of this storm with the heaviest swath of snow 8 to 12 inches favoring an area from central to northeast Minnesota into far northwest Wisconsin, while the North Shore of Lake Superior from the north side of Duluth up along the Higher Terrain of the North Shore has a potential to pick up 12 to 15 inches of snow due to lake and terrain enhancements.
*Lesser snowfall amounts across far northern Minnesota, a range from 6 to 8 inches, lowest amounts the farther north you go.
*That will also be the case across northwest Wisconsin where the greatest snow totals will be found in the northern portion of northwest Wisconsin with lesser amounts of snow farther south in northwest Wisconsin.
*I’m still expecting the snow to mix with or change over to sleet, rain or freezing rain on Thursday, primarily over northwest Wisconsin, but this potential extends farther west into eastern Minnesota, and north to Duluth and Two Harbors as well.
Radar loop ending at 6:15 PM CST, Wednesday, December 26, 2018
There will be no shortage of moisture with this storm as seen in the PWAT chart from 5 PM Wednesday. Southerly flow ahead of a surface low over north Texas will pump deep low level moisture north into the upper Midwest during the next 24 hours.
Pink=Winter Storm Warning
Purple=Winter Weather Advisory
Closer view of the winter weather headlines that are in effect across the Northland.
18z NAM-WRF model
Simulated radar forecast valid from 7 PM this Wednesday evening thru Friday night.
Snow will overspread the Northland from SW-NE tonight, then as temperatures warm both at the surface and aloft will see the snow transition to a mixture of precipitation in far eastern Minnesota and northwest Wisconsin during the day Thursday while snow continues where the temperatures will remain cold enough across northern Minnesota.
The mix of precip in northwest Wisconsin will then switch back over to snow Thursday night as colder air advects in behind the surface low.
As mid level lapse rates steepen Thursday afternoon/evening will likely see a bit of a transition to convective type snow bursts where the snow will come down heavily for brief periods of time. These heavier snow bursts will be embedded in a larger area of lighter snowfall which will cover much of northeastern Minnesota.
Storm Timeline for Duluth and Superior
The snow is coming!
…Winter Storm Warning from 9 PM tonight to Noon CST Friday…
Snow arrives 11 PM-1 AM tonight.
New snowfall of around 2 to 4 inches is possible by 7 AM Thursday.
Snow continues through the day Thursday and into Thursday evening, snow tapers off to light snow and flurries Friday morning.
Potential for the snow to mix with or change to sleet or freezing rain at times on Thursday, if this happens, then that could reduce snowfall amounts just a bit.
Winds: East to northeast at 10 to 20 mph through Thursday evening, gusts to around 30 mph. Winds shift to the north Thursday night.
E-NE wind coming off Lake Superior could cause some lake enhanced or terrain enhanced snowfall through Thursday evening, however, the airmass isn’t very cold, so I’m not real sure if we’re going to get much contribution from Lake Superior, but the potential is there.
Links to road conditions
Wisconsin — https://511wi.gov/map#:Alerts