textproduct: Duluth

KEY MESSAGES

- Warm, dry conditions continue today before a dry cold front moves through tonight.

- High pressure behind the cold front will keep the warm and dry conditions in the region for most of the work week.

- Next chance (~40%) for precipitation will be Friday into the weekend.

UPDATE

Issued at 222 AM CDT Mon Oct 19 2026

Forecast remains on track. Only notable changes from the NBM were to bump up Max temperatures given the warm air mass over head and abundance of clear skies. Min RHs were also lowered for today. Most guidance wants to keep the values around 30% for northern MN and 40% for NW WI. However, model soundings show air as dry as 10% above 3000ft. With the over achieving temperatures we have been seeing the past couple days, it is very plausible that we mix deeper and tap into some of this drier air. Min RHs were lowered to around 25% for northern MN. Fortunately, with the high pressure overhead, winds will be very light through the day.

DISCUSSION

Issued at 121 PM CDT Sun Oct 18 2026

For the rest of the day, a weak and moisture-starved cold front will slide southeastward across the Northland. While the boundary will bring a wind shift from the southwest to the northwest, no precipitation is expected due to dry air aloft. Deep mixing will maintain breezy conditions through the late afternoon before the pressure gradient relaxes this evening. Because the NBM guidance continues to have relative humidity values that are too high for today, forecast values have been lowered into the 25 to 40 percent range to align with observed trends over the past few days.

On Monday, broad surface high pressure builds across the Upper Midwest, leading to a quiet and sunny start to the work week. An exceptionally dry air mass aloft will remain settled overhead. NBM guidance again projects relative humidity values that are too high for Monday, so daytime minimum relative humidity has been lowered to between 25 and 45 percent to maintain consistency with recent dry trends. Winds will shift to the north and east at very light speeds, so critical fire weather conditions are not expected.

Heading into Tuesday and through the middle of the week, a stable omega blocking pattern becomes firmly established across the central United States. Under the influence of the upper-level ridge, unseasonably mild and dry conditions will prevail across the Northland. High temperatures will run well above mid-October climatological averages, reaching into the 60s and lower 70s inland. Afternoon lake breezes will develop along the Lake Superior shoreline at times, keeping immediate coastal areas noticeably cooler and closer to seasonal norms. This high pressure will remain in place for most of the week, which will ensure no precipitation concerns through at least Thursday night.

The soonest chance for more precipitation across the region still looks to be at least next Friday as the blocking ridge begins to break down. Global guidance indicates a closed upper-level low over the Great Basin will eject northeastward toward the Upper Midwest, phasing with a shortwave trough advancing across the Northern Rockies. While timing confidence remains somewhat limited due to the stubborn nature of omega blocks, moisture advection will increase cloud cover and introduce low shower chances Friday afternoon into Friday night. Temperatures will remain unseasonably warm ahead of the system, keeping all potential precipitation strictly in the form of liquid rain.

Showers may linger into Saturday as the trough axis crosses the Upper Great Lakes, but widespread or heavy accumulations are not anticipated. Dry conditions are currently expected to return afterwards as high pressure rebuilds behind the departing wave. Temperatures will trend back toward seasonal values for late October in the wake of the front, likely bringing an end to the extended unseasonably warm stretch.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 623 AM CDT Mon Oct 19 2026

Little bit of morning fog at BRD that should disperse quickly this morning. Surface high pressure moving across the International Border today will lead to mostly clear skies and light winds. VFR conditions through the TAF period with the exception of the fog at BRD this morning.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 222 AM CDT Mon Oct 19 2026

Surface high pressure moving across the International Border will keep winds light and variable to start the day with northeast becoming more dominant in the afternoon and evening. Winds will gust up to around 20 kts at the head of the Lake. Similar set up for Tuesday with wind speeds light in the morning and slightly increasing in the afternoon. Winds will then shift to out of the southwest for Wednesday. Overall, a stagnant weather pattern for the work week is not expected to bring any hazardous conditions for small vessels.

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

FIRE WEATHER

Issued at 222 AM CDT Mon Oct 19 2026

Surface high pressure will be moving across the International Border through the day. Most guidance would suggest that Min RHs will be around 30% for northern MN and 40% for NW WI. However, model soundings show air as dry as 10% above 3000ft. With the over achieving temperatures we have been seeing the past couple days, it is very plausible that we mix deeper and tap into some of this drier air. Min RHs were lowered to around 25% for northern MN and 35% for NW WI. If we are able to mix deeper, expect this RHs to drop closer to the lower 20s for northern MN and lower 30s for NW WI. Fortunately, with the high pressure overhead, winds will be very light through the day.

The dry air mass exits to the east on Tuesday allowing for some recovery in RHs as southerly winds stream back into the region. The weather pattern remains inactive through most of the work week with the next best chance of rain arriving on Friday.

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

DLH WATCHES/WARNINGS/ADVISORIES

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