There’s been some changes for the system on Thursday and also the one for Friday.
Thursday’s system has been trending snowier in model guidance with much of the Northland now expected to get some snow out of this system, with heavy snow possible in the Arrowhead where SSE winds will provide lake enhanced snowfall generally northeast of Silver Bay, including for the cities of Tofte, Lutsen, Grand Marais, Hovland and Grand Portage.
As for Friday’s system, there’s been a slight northward shift in the storm track in model guidance, but even with this slight shift to the north, it’s still not enough to put the Northland into the heaviest snow, but it is enough to where a few inches of snow could accumulate primarily over portions of northwest Wisconsin, say from Shell Lake and Hayward, northeast toward Mellen and Hurley.
The weather pattern will quiet down in our area for this weekend into early next week, but all eyes will be on a potential major storm which may impact the Northern Plains and upper Midwest toward the middle/end of next week (~December 15-17). More on this storm down below.
Here’s the setup for Thursday — A few areas of low pressure approaching from the west with a broad southerly flow occurring ahead of those lows which leads to a warm air advection and moisture advection pattern across our area. There’s no shortage of moisture as precipitable water is forecast to climb to around a half inch or so which is pretty high for our area in December. The amount of lift looks sufficient as well on Thursday.
The issue comes down to the amount of precip/snowfall we see as there are big differences in the computer models when it comes to that.
The NAM guidance has really taken off in terms of how much snow this system will produce on Thursday with a general 2-5″ snowfall in much of northeast Minnesota and northwest Wisconsin while the European model shows a lot less snow except in the Arrowhead and for eastern portions of northwest Wisconsin. The majority of the computer models are siding more with the NAM guidance (although with slightly lower snow amounts) compared to the Euro model.
Snow is expected to develop early Thursday morning over parts of northeast and east-central Minnesota and northwest Wisconsin with snow continuing during the day Thursday before ending from west to east late Thursday afternoon/early evening.
For Duluth and Superior: Some snow is possible after 3 AM tonight, with a better chance for some snow coming in the 7 AM to 1 PM Thursday time frame.
18z NAM 3km model simulated radar forecast valid from Midnight tonight to 6 PM Thursday.
Trying to come up with a snowfall forecast for Thursday’s system has proven to be a tad difficult this afternoon since the guidance is all over the place, but this is what I’ve come up with for possible snowfall amounts for Thursday.
Note: Bust potential is quite high with this system as snow amounts could end up higher or lower than what I have shown on the map below, could go either way.
…Winter Storm Friday through Saturday morning…
NWS hazards map as of 4:35 PM Wednesday, December 8, 2021.
Areas in red and yellow on the image below have the highest chance for exceeding warning criteria snowfall on Friday (6 inches/12 hours, or 8 inches/24 hours).
Heads up if you have travel plans that take you to southern Minnesota or central Wisconsin Friday into Saturday morning as Moderate to Minor potential winter storm impacts covers those areas.
…Storm Threat mid to late next week (~December 15-17, 2021)…
The upper-level pattern for next week is one that can lead to a storm coming out of the Rockies as will see an upper-level trough dig south across the western U.S. while a strong ridge builds NE across the Midwest and Great Lakes.
The computer models have been hinting at a big storm moving NE out of the Rockies for mid to late next week, but at the moment the storm track is well to our west which puts the Northland squarely on the warm side of this potential system which increases the odds will see rain instead of ice or snow, but since we’re talking about a system that is a week away, we could certainly see the storm track shift, and also for the storm to come in weaker or even stronger than what the computer models show right now.
Even more interesting is the fact the computer models are generating quite a bit of CAPE (instability) for next Wednesday-Thursday, and should this verify, we may even see a few thunderstorms in parts of Minnesota and Wisconsin next week.
Potential storm for mid to late next week may also produce very strong winds, with gusts of 40-50+ mph possible in the Northland Wednesday-Thursday, with near hurricane force wind gusts possible on Lake Superior (70+ mph). Wind direction would be from the south on Wednesday, then out of the west on Thursday.