A powerful storm is expected to impact the Northland Wednesday into early Thursday. There are so many hazards with this storm – they include…
- Heavy Snow Accumulations
- Blowing and Drifting Snow
- A period of blizzard conditions possible Wednesday afternoon/Wednesday evening
- Isolated power outages
- Rapidly falling temperatures
- Dangerously cold wind chills Wednesday night/Thursday morning
- Some rain, fog and mixed precipitation on Wednesday
- Potential for a flash freeze
I’m going to try and break down all the hazards as best I can, but keep in mind this storm is still evolving and changes are certainly possible especially when it comes to snowfall amounts and what areas of the Northland see the most snow.
To those who just want a snowfall forecast instead of reading through my mumbo jumbo, here ya go!
For Duluth and Superior I’m going with 8-12 inches of snow with the heaviest snow/worst conditions expected to occur from late Wednesday afternoon through Wednesday evening, this is when we could see times of whiteout/possible blizzard conditions in the Twin Ports.
Wednesday morning into early Wednesday afternoon in the Twin Ports should feature some fog, drizzle, and maybe some sleet at times with patchy icing. Snow gets going Wednesday afternoon.
Note: A Winter Storm Warning is in effect Wednesday and Wednesday night for northern, northeast and east-central Minnesota including International Falls, Bigfork, Cass Lake, Walker, Brainerd, Aitkin, Moose Lake, Cloquet, Duluth, Hibbing, Ely, Two Harbors, Silver Bay and Grand Marais, while a Winter Storm Watch is in effect Wednesday and Wednesday night for northwest Wisconsin and a small part of eastern Minnesota including Hinckley, Pine City, Superior, Washburn, Bayfield, Ashland, Hurley, Grantsburg, Siren, Minong, Shell Lake, Spooner, Hayward and Winter, this watch will likely change to a warning or advisory sometime this evening.
…Timing of Precipitation/Precipitation Types
12z European model precipitation type forecast for the times listed on the images below.
Snow to the west, rain or a mix to the east Wednesday morning/early Wednesday afternoon.
Rain switches over to snow in eastern areas Wednesday afternoon/early Wednesday evening, while snow continues to fall out west.
Snow across the entire area Wednesday evening, tapering off to flurries in western areas.
Light snow and flurries linger late Wednesday night into early Thursday morning, with heavier lake effect snow showers along the South Shore of Lake Superior in northwest Wisconsin.
There could be some areas of snow or possibly a mixture of precipitation types across far northern Minnesota tonight, otherwise it looks mainly dry in the Northland tonight.
Snow, rain and mixed precipitation becomes widespread across the entire area on Wednesday with any rain/mixed precip turning over to snow later in the day.
Snow tapers off late Wednesday night-early Thursday morning.
Here’s the 18z NAM 3km model simulated radar forecast valid from 6 PM this evening to 7 AM Thursday.
…Temperatures and Flash Freeze Potential…
Expect rapidly falling temperatures across the Northland on Wednesday.
Wednesday morning will start out on the mild side across the entire area with temperatures in the upper 20s to middle 30s, but arctic air will rush into western areas of the Northland by early Wednesday afternoon as temperatures drop into the single digits and teens, while warm air hangs on across eastern Minnesota, northwest Wisconsin and along the North Shore, in fact there is a chance that temperatures early Wednesday afternoon range from around 40 degrees in Hayward, to around 10 to 15 degrees along a Brainerd to Grand Rapids to International Falls line. The arctic air will then move into eastern Minnesota and northwest Wisconsin from W-E across those areas late Wednesday afternoon thru early Wednesday evening with temps rapidly falling into the single digits and teens in those areas.
Note: Temperatures in Duluth and Superior are forecast to range from around 32 to 36 degrees Wednesday morning into early Wednesday afternoon, but then will see the temperature drop rapidly, falling to around 20 by around 3 PM, and single digits by 7 PM Wednesday.
With such a rapid drop in temperatures, there is a chance that some parts of the Northland could see a flash freeze where wet and or slushy roads/sidewalks turn to a sheet of ice in a matter of minutes as the cold arctic air rushes in Wednesday afternoon/early Wednesday evening.
Note: Wind chills of 10 below to as cold as 30 below zero are expected in the Northland Wednesday night.
18z HRRR model temperature forecast valid 6 AM Wednesday to Midnight Thursday.
Watch how the arctic air (outlined in blue) spreads south/east out of the Red River Valley on the animation below.
…High Wind Potential…
North to northwest winds will increase from west to east across the Northland on Wednesday, with gusty winds developing first across north-central Minnesota ~7 to 11 AM Wednesday, then spreading further east and reaching northwest Wisconsin by late Wednesday afternoon or early Wednesday evening.
Widespread winds of 15 to 25 mph are likely throughout the Northland Wednesday into early Thursday, with wind gusts of 30 to 50 mph possible especially across north-central, northeast and east-central Minnesota including the North Shore of Lake Superior. Note: The strongest winds are expected Wednesday afternoon through Wednesday night.
Strong N-NW winds develop in Duluth and Superior Wednesday afternoon (~1 PM to 3 PM) and will continue through Wednesday night with wind gusts up to around 45 mph possible.
Note: There will be a risk for sporadic power outages across the Northland due to the potential for high winds Wednesday afternoon into Wednesday night.
12z European model max wind gust forecast valid 6 AM Wednesday to 6 AM Thursday.
A strong mid/upper level trough is moving east across the Rockies this afternoon and will make its way into the Northland on Wednesday.
Here’s how the trough looks on water vapor imagery from today, Tuesday, December 22, 2020.
Power Outage Maps
Minnesota Power: https://mnpower.com/OutageCenter/OutageMap
Lake Country Power: http://outage.lcp.coop/