textproduct: Duluth

KEY MESSAGES

- Unseasonably warm today and to a lesser extent tomorrow.

- A long duration system arrives Monday afternoon with rain mixing with snow Tuesday then changing over to all snow Tuesday night into Wednesday. Accumulating snow across much of the region is becoming more likely.

- Colder air moves in Wednesday and lasts into the weekend bringing below normal temperatures with another system possible for the weekend.

DISCUSSION

Issued at 429 AM CST Sun Nov 23 2025

High pressure was located near Sioux City early this morning with the surface ridge axis extending northward into the Red River Valley of the North. A warm front was located across the western Dakotas and was leading to cloud cover across North Dakota into northwestern Minnesota. Another area of cloud cover was located across northwestern Ontario into the Minnesota Arrowhead in association with an area of low pressure just to the northeast of Lake Superior. The ridge axis will move overhead today with winds turning southerly as the day progresses bringing warmer air into the Northland. Highs will be in the 40s and lower 50s which is around 10 to 15 degrees above normal. A bit of cooler air arrives on Monday behind a dry cold front. Highs will still be above normal in the 40s.

Heading into Monday night, our well advertised system will start to affect the Upper Midwest. The 23.00 suite of models have slowed down the onset time of rain moving into the region to Monday night into Tuesday morning. This rain will be front a shortwave and surface low pressure moving northeast across the Mid-Mississippi Valley. Trends have been a bit further south recently with this feature resulting in the delayed onset time. There is also a chance that it remains further south and only clips parts of northwest Wisconsin. Heading into Tuesday, the more impactful part of the system will arrive as an upper low moves out of the Northern Plains and into the Upper Midwest. Cooler air will also be arriving through the day on Tuesday leading to rain mixing with snow before changing over to all snow from northwest to southeast Tuesday night. Snow will then slowly taper off from west to east on Wednesday. Strong northwesterly winds on the backside of the system may lead to areas of blowing snow as even cooler air filters in.

With all that said, there still remains questions as to the evolution of the system, the track of the low, and how much moisture will be available. Models seem to be fairly consistent in tracking the low across our southern CWA Tuesday into Wednesday, which would keep us out of the dry slot for the most part leading to higher precipitation potential. The track of the low also hints at the potential for a TROWAL setting up across the Northland somewhere which would lead to heavier snowfall amounts underneath. Additionally, Thaler QG-omega progs are strongly negative over the Northland as the system moves through which would lead to enhanced lift and higher snowfall amounts as well. One of the big questions remaining is how much moisture will be able to work northward into the region. Models vary on this, but overall have been trending wetter. PWAT values aren't overly high, but are still in the 75th percentile or higher for the date.

Continuing with the format started be the previous forecaster, here are the latest thoughts on probabilities for certain snowfall amounts:

>= 1": 50-80%, highest in northern Minnesota and the South Shore. >= 4": 20-50% in east-central Minnesota and northwest Wisconsin away from Lake Superior, and 50-70% in northern Minnesota and the South Shore. >= 6": up to 20-50% mainly across the Arrowhead. Up to 40-70% in Iron Co, WI. >= 10": Best chance (30-50%) in northern Iron Co. 10-20% chance somewhere in far northeast Minnesota.

These probabilities include lake-effect snowfall along the South Shore that will linger into Thursday night. Sfc-850 delta Ts will be 15 to 20 degrees (and perhaps higher!) which would result in lake induced CAPE of 500-700 J/kg. This should really get the lake effect machine going across northern Iron County for Wednesday into Thursday with the heaviest snow expected Wednesday into Wednesday night.

The cold air will remain in place over the remainder of the week and into the weekend with highs in the 20s and overnight lows in the teens and single digits above zero. Models continue to hint at another large system affecting the central CONUS for the weekend. Given the cold temperatures, this will be all snow and may lead to travel impacts while trying to return home from the Thanksgiving holiday as well.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 541 AM CST Sun Nov 23 2025

VFR conditions will prevail through the TAF period. There may be some LLWS at HYR tonight, but potential is too low to include with this update.

MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 429 AM CST Sun Nov 23 2025

Winds will continue to weaken today as high pressure moves over western Lake Superior. Westerly winds this morning at 10 to 20 knots will become southwesterly this afternoon and tonight at 5 to 15 knots. Stronger gusts to 20 to maybe 25 knots will be possible across the Outer Apostle Islands tonight and may lead to a period of conditions hazardous to small craft. Winds Monday will slowly diminish to 5 to 10 knots out of the west to southwest by afternoon. Winds turn northeasterly on Tuesday as the next system approaches with conditions hazardous to small craft starting Tuesday night with gales possible as well late Tuesday night into Wednesday night.

For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt.

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None. MARINE...None.