textproduct: Duluth

KEY MESSAGES

- Light snow and mixed precipitation is likely along and north of the Iron Range and in the Arrowhead this morning, ending last in the tip of the Arrowhead this afternoon. Snow accumulations of a trace to 0.5 inches and a very light glaze of ice are possible.

- Seasonally mild and mostly quiet weather Sunday into early Monday.

- A messy early winter system is in the forecast Monday afternoon through Thursday next week. Rain, snow, and strong winds are all possible. Rain and snow amounts are still uncertain, but have been trending up.

- A stark pattern change with below average temperatures is expected midweek and into at least early December.

DISCUSSION

Issued at 356 AM CST Sat Nov 22 2025

Today - Tonight:

As of 3 AM CST this morning, a surface low was located near the ND/MN/Canada border. Warm advection processes on the north side of this low and mid/upper-level support for lift should be enough to produce a light wintry mix along the International Border and in the Arrowhead from early this morning through around midday, with precipitation moving out of the tip of the Arrowhead this afternoon. Temperatures will generally be below freezing until mid to late morning, so expect a few hours where light snow, freezing rain/drizzle, and rain could all occur this morning before changing to mainly rain towards midday as temperatures warm above freezing. The potential for freezing rain to mix in is due to a subtle nose of above-freezing temperatures aloft in the atmospheric thermal profile. Overall, any precipitation should be light with QPF amounts of 0.01-0.1", trace up to 0.5" of snow, and patchy accumulations of a light glaze of ice.

Cloud cover gradually clearing from southwest to northeast throughout the day should allow most of the Northland to warm into the 40s aside from some upper 30s in the tip of the Arrowhead, and near 50F for far southern portions of the area.

One thing to watch this evening and tonight will be a signal for downslope/katabatic winds along the North Shore as the low/cold front push east of the area. This could produce a few hour period of gusty northwest winds of 30-40 mph. Not expecting Wind-Advisory level winds gusts (45+ mph) at this point, but there is a 10-30% chance that could occur.

Sunday - Early Monday:

Mainly dry and mild for Sunday and early Monday as a surface and upper-level ridge move over the region. High-resolution models do show some modeled precipitation around or just north of the International Border Sunday morning and afternoon, but dry air in the low-levels of the atmosphere and a lack of support for lift aloft should keep the Northland dry. Looks for widespread highs both days in the 40s to around 50F, warmest south.

Monday Afternoon - Thanksgiving Day:

The main update to provide here is that while there is still some uncertainty on low pressure tracks and that effect on when rain will transition to snow and how much snow we will see, global ensemble model guidance has been coming into better agreement on an increasing trend in snowfall probabilities in the Northland for the Tuesday - Thanksgiving timeframe.

Two upper-level features to keep an eye on will be a trough approaching the Pacific Northwest on Sunday, that will deepen as it crosses the Northern Plains and Upper Midwest, with most guidance having it deepen to a closed upper-level low as it moves into the northern Great Lakes late Tuesday/Wednesday. At the same time, a cut-off upper-low west of Baja California today will traverse the Four Corners and Front Range of the Rockies on Sunday and Monday before ejecting northeast into the Great Lakes on early to mid-Tuesday, eventually joining the upper-flow just ahead of the deepening upper-low over the Upper Midwest. The southern low should work to bring in some moisture originating in the western Gulf, with parts of the Northland expected to see PWATs approach 0.7-0.8" (95-98 percentile of climatology for this time of year). That higher moisture does drop off a bit into late Tuesday (PWATs down to 0.5 to 0.6) before decreasing farther into Wednesday and Thursday. This should be sufficient moisture given the strong synoptic forcing associated with these systems to support widespread rainfall. It appears that the two upper-lows will be interacting with each other in a way that supports a surface low deepening as it moves northeast through the Upper Midwest through the upper Great Lakes. Still some uncertainty in how these lows track, but generally speaking it has led to increasing probabilities of precipitation amounts, both for rain and snow.

Mild temperatures on Monday and overnight lows into Tuesday morning mostly above freezing should support light to moderate rain as the primary precipitation type at onset as early as Monday afternoon. Rain chances expand across the area into Monday night and early Tuesday, with brief, localized heavy rain at times. Through the whole event (Monday to Thursday), QPF from rain/melted mixed precip would generally be in the 0.3-0.75" range, though some locations along the North and South Shores could see amounts approaching 1" given terrain and lake enhancement. Areas where a likely TROWAL/banded precipitation region on the northwest side of the surface low pressure center track over could also see upwards of 1" of rain/melted mixed precip. This region may still shift, but north-central Minnesota is currently the most favored to see it.

As temperatures begin to drop from west to east starting daytime Tuesday, rain should gradually mix with snow and then change over to all snow Tuesday night into Wednesday as temperatures drop below freezing. One caveat with regards to precipitation late Tuesday/Tuesday night will be whether or not a dry slot region moves into the Northland to the southern and southwestern side of the surface low. This potential will be highly influenced by where the surface low tracks as a dry slot here would likely cut off precipitation for a time before wrap around snow on the backside of the low would come into play. However, areas northwest of the dry slot would also be in/near the TROWAL/banded snow region, so those locations would be likely to see heavier snow depending on where it sets up late Tuesday into early Wednesday. The surface low should slowly track far enough northeast late Wednesday into Thursday that the remaining precipitation would be in the form of lighter, fluffier snow as a much colder airmass moves into the region. 850-mb temperatures of -10C to -15C and northwest surface winds could keep lake-effect/enhanced snow going into portions of the South Shore as late as Friday depending on how much low-level moisture hangs around. Some larger inland lakes in Minnesota-- which are still open water--could also get in on the lake-effect snow action given the colder temperatures.

The latest probabilities for snow amounts and favored locations for Tuesday - Thursday (as of this morning's forecast) are as follows:

>= 1": 30-80%, highest in northern Minnesota and the South Shore. >= 3": 15-60%, highest along/north of Iron Range and in Iron Co, WI. >= 6": up to 20-40% in north-central Minnesota and along/north of the Iron Range. Up to 20-50% in Iron Co, WI.

There is a smaller subset of model ensemble members with much more than 6" for Iron County (i.e. 10-12"+), which would depend on the intensity of lake-effect/lake enhancement processes with this system.

In addition to the precipitation, this tightly wound system will bring gusty winds with it as it passes through the region. While it will be breezy from Tuesday through Thanksgiving Day, the strongest gusts would be late Tuesday and Wednesday. As of now, there is a 10-30% chance for wind gusts of 35+ mph on Wednesday, which could lead to blowing snow and reduced visibility depending on how much snow will have fallen and if snow is still ongoing.

Next Weekend:

Snow that falls is likely to stick around on the ground as temperatures (high and low) remain below freezing Thursday into next weekend, with a cold pattern sticking around into early December. Model depictions of the upper-level weather pattern diverge next weekend, but there is the possibility for the active weather pattern to continue with another system as early as next weekend.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 552 AM CST Sat Nov 22 2025

Some scattered, light rain/freezing rain/snow showers with low pressure skirting the Canadian Border has largely remained north of INL. However, as the morning progresses, INL could still see some VCSH or occasional light wintry mix through around 16Z with a temperature around freezing. Minimal accumulations expected. MVFR ceilings have already started at INL and should persist through most of the day (60-70% chance). Other terminals remain VFR, though some scattered cloud bases around 2500 to 3000 ft will be possible at HIB/DLH. Some LLWS is possible through 15Z at DLH and HYR before surface winds increase. Winds increase this morning and shift to westerly as by late morning to afternoon, with daytime to early evening gusts of 15-21 kt before weakening again this evening. Additional LLWS is possible at DLH/HIB/HYR this evening and tonight underneath a 40-45 kt 850 mb jet.

MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 356 AM CST Sat Nov 22 2025

Some light rain or mixed precipitation is possible for the North Shore this morning into early afternoon. Light southerly winds early this morning increase out of the southwest today and then turn westerly behind a cold front this evening into early Sunday morning. Gusts this afternoon into early Sunday morning could approach 20 to 30 kt, strongest in the Apostle Islands and portions of the North Shore along and north of Silver Bay. Small Craft Advisories are in effect for this afternoon into early Sunday. Additionally, there is a 20-40% chance for gale- force wind gusts northeast of Silver Bay due to expected downslope/katabatic winds along the North Shore spreading out a couple miles into the nearshore waters. Winds weaken on Sunday as they slowly back to the southwest.

Attention turns to an active weather system that will move through Monday through Thursday next week. Windy conditions are likely Tuesday through Thursday. Gales may be possible at times. This system will also bring rain on Monday into Tuesday, a rain/snow transition late Tuesday, and then to snow for Wednesday that will gradually taper off into Thursday for most of western Lake Superior.

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...Small Craft Advisory from 2 PM this afternoon to 6 AM CST Sunday for LSZ121-146>148-150. Small Craft Advisory from 2 PM this afternoon to 8 AM CST Sunday for LSZ140>142. Small Craft Advisory from 2 PM this afternoon to 4 AM CST Sunday for LSZ143>145.