textproduct: Duluth

KEY MESSAGES

- Widespread rainfall moves in later this afternoon through Tuesday, lingering into Wednesday.

- Areas of fog possible tonight into Tuesday morning, especially near Lake Superior.

- Warm temperatures through Wednesday, then cooling down Thursday and into the weekend.

- Frost and freezing low temperatures are expected starting Thursday night and lasting into the weekend.

- More rain is possible this weekend.

DISCUSSION

Issued at 113 PM CDT Mon Sep 28 2026

Morning fog has been lifting with residual stratus in spots across northwest Wisconsin and east-central Minnesota late this morning. This is largely expected to continue mixing into stratocumulus through the afternoon. Overhead, higher clouds are moving in from the west in advance of an approaching low and warm front in North Dakota. This warm front will be the focus for some decent rainfall accumulations that are largely expected to remain approximately over the Red River valley, where persistent warm air and moisture advection should interact with the warm front to produce a quasi-stationary band of rain overnight. Several inches of rain will be possible there, while we get a glancing blow with some amounts perhaps approaching an inch for parts of Koochiching County. Some embedded thunder is possible as well with some modest instability overnight. In addition, look for more fog tonight. With synoptic southerly flow and easterly flow off Lake Superior, the best chance will be along the North Shore terrain and also around Lake Superior. While areas of dense fog may be possible, there isn't enough confidence that it will be widespread enough to warrant headlines (~50-70% chance of visibility <1/2 mile).

Going into Tuesday and Tuesday night, we'll look for a secondary upper level trough to pass through, and this will bring another round of rain east through the region. It's looking like this rain will be more transient, so a quarter inch to an inch of rain for the rest of the region Tuesday into Tuesday night. Any risks for flooding with this rain look really low overall. The only small concern is if the banded rain tonight extended a bit further northeast than forecast, which could put parts of Koochiching county into a chance for seeing over an inch of rainfall. Even if that happens, the risk for flooding would remain low.

There could be some lingering rain in northwest Wisconsin on Wednesday, but most activity should be to our southeast by then. Overall, it's looking like we should see clearing skies with warm temperatures in the 70s across the region Wednesday afternoon as we see warm west to southwest flow through the day.

Wednesday night, a pretty potent cold front is expected to pass through. We should see a pretty abrupt switch to northwest winds and cold air spilling in from Canada. Plenty of dry air will accompany this front, so we're not expecting rain. Temperatures will be noticeably cooler (highs in the upper 50s to low 60s) Thursday along with brisk and breezy northwest winds. The winds will subside in the evening with high pressure settling in and skies becoming mostly clear. It's looking like a near-perfect radiational cooling night. A widespread frost is likely for most places except possibly for some areas around Lake Superior. Temperatures will probably drop below freezing for many places too (50-70% chance in the usual cool spots). Frost and freeze headlines will likely be needed.

Quasi-zonal flow will keep the weather quiet Friday, and we'll watch for another upper-level trough and low pressure system to move in sometime around Saturday. Lows Friday night may fall into the 30s again for many places, but with clouds moving in overnight, frost may be a bit more patchy. The low passing through Saturday is essentially a clipper system, so a quick hitting rain with accumulations likely only topping out around a quarter inch followed by a reinforcing cold front Saturday night. Winds and clouds Saturday night should keep frost very minimal, if not non-existent, though temperatures will still be on the chilly side.

Sunday into Monday, it's looking like we will end up with mainly dry conditions and high pressure setting up. We may see another cold night with frost/freeze conditions Sunday night. A little lingering moisture could stick around depending on placement of an upper-level trough aloft. If we do hold on to some moisture, it wouldn't be out of the question for a few snow flurries somewhere, most likely the Arrowhead, but predictability for that is very low right now.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 113 PM CDT Mon Sep 28 2026

MVFR ceilings persist around HYR/BRD this afternoon. Expect modest improvements this afternoon as stratocumulus mixes a bit, but more clouds will be streaming in from the west this evening into tonight with rain accompanying. Visibility is expected to hover between VFR and MVFR at most terminals tonight with periods of mainly light rain. Ceilings will generally trend MVFR with IFR conditions at INL as they will be closest to the main axis of rainfall that will be located over northwest Minnesota tonight. Winds will generally remain southerly through the period with some onshore winds from the southeast at times at DLH. Winds will be breezy at times with onshore flow at DLH this afternoon, then generally light overnight. Strengthening winds again at all terminals Tuesday morning with gusts in the 15-20 kt range.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 331 PM CDT Mon Sep 28 2026

Update: Added dense fog advisories for most of the South Shore through this evening. Satellite and webcam shows dense fog in place around Saxon Harbor, and this should expand over the next few hours as models suggest. Southerly winds may cause fog to expand further north later tonight, and more dense fog advisories may be needed.

Previous Discussion: Light northeast winds tonight, becoming southerly along the South Shore. On Tuesday, wind speeds will increase and gusts up to 15 to 25 kt are expected during the afternoon and evening. There is high enough confidence in ~25 kt winds around Grand Portage Tuesday into Tuesday evening that I issued a Small Craft Advisory with this update. Waves up to 4 ft are expected there as well. Along the South Shore, 20-25 kt winds are possible (40% chance) as well, but since conditions are marginal, I will hold off on Small Craft Advisories there for now. Waves are not expected to be a concern there. Expect rain to move in later tonight and persist through Tuesday and Tuesday night at times. Thunder is not expected.

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

FIRE WEATHER

Issued at 113 PM CDT Mon Sep 28 2026

A widespread wetting rain is expected starting tonight and persisting through Tuesday night. A few places may see slightly less than a quarter inch in total, but most locations should see between a quarter and one inch with locally higher amounts possible in and around Koochiching County. With the rain, RH will remain high and fire weather conditions will remain minimal even after rain clears out to some sunshine on Wednesday. RH is expected to remain above 50 percent. A potent and dry cold front will pass through Wednesday night into Thursday with breezy northwest winds gusting to 15 to 25 mph. Temperatures will be cooler, but dry air will result in min RH falling to around 30 to 45 percent, perhaps leading to slightly elevated fire weather conditions. Similarly dry conditions are expected Friday, but with light winds. Another round of mainly light rain is expected on Saturday.

See the Fire Weather Forecast product for a more thorough breakdown of fire weather conditions.

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None. MARINE...Dense Fog Advisory until 1 AM CDT Tuesday for LSZ121-146>148- 150. Small Craft Advisory from 10 AM to 10 PM CDT Tuesday for LSZ140.