textproduct: Duluth

KEY MESSAGES

- Widespread frost and freeze conditions are expected early Friday morning. Additional frost and freezing temperatures are expected again Friday night.

- Light rain is expected Saturday into Saturday evening, especially along the International Border.

- Another widespread frost/freeze is expected Sunday night into Monday morning.

DISCUSSION

Issued at 140 AM CDT Fri Oct 2 2026

For the overnight hours and early this morning, winds are very slowly decreasing in speed. However, they will remain elevated for the Arrowhead and North Shore, which will largely help impede any frost formation there. Where the winds have cut off, very spotty temperatures down to freezing have already been observed. Frost potential is expected to expand in coverage over more areas towards the early commute hours this morning and especially by sunrise. All previously issued frost and freeze headlines remain in effect until 9 AM. After sunrise, a short-lived uptick in gusty north-northwest winds is expected for far northern Minnesota. Downsloping valleys on the North Shore could see a few hours of wind gusts to 30 mph through mid-day today before winds quickly become nearly calm by late afternoon.

For tonight, a more limited coverage of frost and freeze conditions is expected, starting late this evening and lasting through the pre-dawn hours Saturday. A second round of Frost Advisories is in effect for the tip of the Arrowhead, as well as parts of northern Wisconsin. North Shore communities right along the shorelines are not expected to see frost, with lows in the upper 30s compared to the low 30s for the terrain ridge and further inland. Iron County has an 80-90% chance of seeing sub- freezing temperatures Friday night so this is the sole county with a Freeze Warning for Friday night. Incoming cloud cover from the west will limit how much temperatures can bottom out for most of northeast Minnesota, and better mixing from increasing southerly winds creates no frost concerns for the Brainerd Lakes to Leech Lake region Friday night.

This incoming sky cover is associated with a shortwave moving along the International Border later Friday night into the daytime hours of Saturday. We will see increasing light and spotty rain shower chances of 30 to 50 percent for the Iron Range northward early Saturday morning. Highly localized spots could see up to a couple of tenths of an inch of rain. As the associated cold front moves over the region later Saturday afternoon, these rain shower chances will spread southward along the front, finally reaching northwest Wisconsin by Saturday evening.

A trailing and much cooler airmass aloft will move in on northerly flow for Sunday. Breezy northerly winds gusting 25 to 30 mph from mid-day into the early evening. As these winds slowly decrease Sunday evening, ideal radiational cooling will set up. This brings the best chances of this entire stretch for a freeze potential to most of the region late Sunday night into early Monday morning. Widespread freeze warning headlines may be needed in time for this period; the exception might still be the Brainerd Lakes area into central MN remaining only into the mid-30s.

Heading into the next work week, temperatures will slowly warm as the overall flow shifts back to a southerly component. Highs will climb into the upper 60s, scraping the 70s by mid-week. While a few periods of very light and spotty rain showers cannot be ruled out, there is only a 10-20 percent chance of this occuring so the extended forecast is largely dry and pleasant.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 620 AM CDT Fri Oct 2 2026

VFR conditions prevail. There will be a few hour period of gusty north-northwest winds at most terminals through 20Z today, as winds gust to 20 knots...mostly for the Twin Ports into the Arrowhead and especially along the North Shore. Winds become calm from 21Z - 00Z this evening. Expect a shift to southeasterly after 06Z and increasing to around 10 knots in north-central Minnesota to end this TAF period.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 132 AM CDT Fri Oct 2 2026

Northwest winds will remain elevated this morning, particularly from Grand Marais to Two Harbors, where a Small Craft Advisory is in effect until 1 PM CDT today for gusts up to 25 knots. Winds will diminish this afternoon and become light tonight. Southerly winds will increase on Saturday ahead of a warm frontal passage Saturday morning, bringing chances for rain showers. A few zones of Advisories may be needed Saturday daytime on the South Shore, but the highest confidence is the Grand Portage zone along the far northern shorelines. Winds will shift to the northwest behind the cold front Saturday night, likely requiring additional Small Craft Advisories for gusts of 25 to 30 knots.

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

FIRE WEATHER

Issued at 128 AM CDT Fri Oct 2 2026

Dry conditions will continue today with northwest winds gusting to 15 mph inland and up to 30 mph near the North Shore, while minimum relative humidity falls into the 30 to 40 percent range. Expect a wind shift to southerly tonight and an increase in wind speeds early Saturday morning first over north-central Minnesota. A passing system brings higher humidity and light rain chances on Saturday mainly to north- central and far northeast Minnesota....a drier airmass remains over northwest Wisconsin into the MN/WI stateline border area through Saturday afternoon. A few showers then may work into northwest Wisconsin Saturday evening, but a wetting rainfall is not expected. These Saturday PM showers will be associated with a cold frontal passage that shifts winds back to northwesterly Saturday night and creates gusty northwest winds by Sunday morning. Drier conditions return on Sunday with minimum relative humidity dropping back to 30 to 45 percent alongside breezy northwest winds gusting 20 to 30 mph.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Freeze Warning until 9 AM CDT this morning for MNZ010-011-019. Frost Advisory until 9 AM CDT this morning for MNZ012-018-025- 026-033>038. Frost Advisory from 9 PM this evening to 7 AM CDT Saturday for MNZ012-021. WI...Frost Advisory until 9 AM CDT this morning for WIZ001>004- 006>009. Frost Advisory from 9 PM this evening to 7 AM CDT Saturday for WIZ003-009. Freeze Warning from 9 PM this evening to 7 AM CDT Saturday for WIZ004. MARINE...Small Craft Advisory until 1 PM CDT this afternoon for LSZ141>143.