6:02 PM Sunday, April 2, 2023
A powerful winter/spring storm could impact the Northland Tuesday into Wednesday.
Potential Storm Impacts for Northeast Minnesota and Northwest Wisconsin
*Significant Snow accumulations (>6″)
*Sleet and Freezing Rain with significant ice accumulations of up to or greater than 0.25″
*Scattered Thunderstorms
*Very Strong Northeast Winds with gusts of 30 to 45 mph, to as high as 65 mph near Lake Superior
*Occasional whiteout/blizzard conditions
*Minor flooding due to snowmelt and rain on top of existing snowpack
*Scattered power outages and tree and power line damage
The storm track continues to be a little uncertain for Tuesday and Wednesday, with a few models farther to the east, while a few others are farther to the west — The storm track shown below is using the Euro and its ensemble model as I have more confidence in that forecast storm track than I do with other storm tracks shown by other computer models.
Based on the Euro model storm track, the chances that precipitation stays as all snow for the duration of the storm in Duluth is low, with a more likely scenario of seeing snow during the day Tuesday changing to sleet and freezing rain Tuesday evening through the overnight then changing back to a little snow Wednesday afternoon/evening. This farther west storm track allows warm air aloft to build north into the Twin Ports Tuesday night causing the snow to switch to sleet and freezing rain which in turn produces less snow than if the storm track stays far enough east allowing cold enough air to stay in place causing mostly snow and much higher snow amounts.
Here’s my preliminary snowfall forecast for Tuesday through Wednesday night.
Highest totals favoring northwest portions of the area with a chance for around a foot or more of snow for International Falls.
Lowest totals favoring east central Minnesota and northwest Wisconsin due to a change over from snow to sleet, freezing rain and rain.
For Duluth: 4 to 6 inches of snow is possible with most of this falling Tuesday into early Tuesday evening. A change over to sleet and freezing rain is expected Tuesday night with a potential for significant ice accumulations. Some additional snow is expected Wednesday afternoon and night, but little additional accumulation is expected.
Note: Duluth picked up 0.8 inches of snow Sunday morning which brings the seasonal snowfall total for 2022-2023 to 129 inches. Duluth still needs another 6.5 inches of snow to break the seasonal snowfall record of 135.4 inches set in 1995-1996.
Should be able to move up from 5th snowiest to 2nd snowiest after this next storm, but I have doubts will be able to take the number one spot this week.
Top 4 snowiest winters on record at Duluth, Minnesota
1: 135.4 inches set in 1995-1996
2: 131.8 inches set in 1949-1950
3: 131.0 inches set in 2013-2014
4: 129.4 inches set in 2012-2013
ICE ACCUMULATION POTENTIAL
There continues to be a possibility for freezing rain with significant ice accumulations Tuesday night through about mid-morning on Wednesday in parts of the Northland, mainly favoring northeast and east central Minnesota into parts of northwest Wisconsin including the Duluth area.
Total ice accumulations of 0.10 to 0.25 inches or more are possible.
Low-end ice total for Duluth is 0.12 inches, the high-end is 0.57″ per today’s 12z EPS model run.
The NWS Blend of Models is made up of many models blended together which is than averaged out, so here’s what the NBM shows for total ice accumulations. Maximum amounts per NBM are sitting in that 0.10 to 0.15″ range.
TIMING
Snow spreads SW-NE across the Northland Tuesday morning with snow continuing Tuesday afternoon followed by a change over to sleet, freezing rain and rain in northwest Wisconsin, and in northeast and east central Minnesota Tuesday night into Wednesday morning. More snow and a mix continue during the day Wednesday.
For Duluth — Snow begins Tuesday morning around 5 AM to 8 AM.
Euro model radar forecast valid from 1 AM Tuesday to 7 PM Wednesday.
Snow (blue)
Mix (orange and pink)
Rain (green)
The storm track will determine how much warm air moves into the Northland Tuesday night/Wednesday morning. A farther west storm track allows warmer air aloft to move into much of northeast and eastern Minnesota including Duluth and all of northwest Wisconsin, while a farther east storm track would likely keep the warmer air confined to parts of northwest Wisconsin with colder air remaining in place in northeast and eastern Minnesota including Duluth.
There is going to be a tremendous temperature gradient setting up Tuesday night with 850mb temperatures as low as -10C in northwest and far northern Minnesota to around +5C in northwest Wisconsin to as high as +12C in southeast Minnesota and southwest Wisconsin.
THUNDERSTORM THREAT
There continues to be a chance that will see a few thunderstorms in northeast and east central Minnesota and northwest Wisconsin as a couple different waves of higher instability lifts N/NE through the area Tuesday afternoon and again Tuesday night/Wednesday morning.
Euro model CAPE forecast valid 7 AM Tuesday to 1 PM Wednesday.
Tim