textproduct: Duluth

KEY MESSAGES

- Hazardous marine conditions today with gale force wind gusts and high waves across western Lake Superior. Wind and waves diminish this afternoon and tonight.

- Additional rain chances late Wednesday/Wednesday night and again Friday into early Saturday. The late week system could bring an inch or more of rainfall south of a line from near Brainerd to Moose Lake to Bayfield.

- Near-normal high temperatures in the mid 60s to low 70s for the later half of the week.

DISCUSSION

Issued at 315 PM CDT Mon Sep 14 2026

Wednesday - Thursday:

A zonal flow pattern aloft sets up for Wednesday and Thursday. Wednesday will be dry to start, but there is potential for some light rain showers (10-40%) across far northern and southern portions of the Northland Wednesday evening into early Wednesday night as the high pressure departs to the east. An additional surface high pressure center passing to our north Thursday should keep that day dry.

Temperatures moderate slightly for Wednesday and Thursday with high temperatures in the mid 60s to low 70s on Wednesday/Thursday, and some mid 70s in the Brainerd Lakes to northwest Wisconsin on Thursday. Relatively warmer lows in the 40s to low 50s (warmest near Lake Superior) Wednesday and Thursday nights should keep any additional frost chances at bay.

Friday - This Weekend:

Another round of showers and thunderstorms are forecast to return to the Northland on Friday through early Saturday. Lee cyclogenesis develops a surface low in eastern Colorado on Thursday and ejects it through the Central Plains Thursday night/early Friday and into the Upper Mississippi River Valley late Friday into early Saturday. The exact track of the surface low and the northward extent of its attendant warm front and warm sector will dictate precipitation potential, amounts, and locations in the Northland for Friday through early Saturday. The ECMWF EFI QPF values with this system do show a swath of 0.5-0.6 (out of a maximum of 1) into portions of inland northwest Wisconsin along with 90th-plus percentile PWATs relative to NAEFS CFSR climatology, suggesting potential for an unusually higher than normal precipitation signal from several EPS members for this time of year. All this is to say that if the surface warm front sets up in the ideal location just south of the area, a low-level jet riding over to the cool side of the front could set up a band of heavier rainfall in southern portions of the Northland, particularly northwest Wisconsin. The WPC Day 5 Slight Risk area also highlights this potential for heavy rainfall. Additionally, the 13Z 9/14 run of the NBM rainfall amount probabilities for 0.5" or greater are 50-75% south of US-2, highest in inland NW WI, but don't drop off much for 1" or greater with probabilities still 40-65% for the same areas.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 107 PM CDT Tue Sep 15 2026

Scattered to broken stratus associated with the upper low continues to move across the area today, with a mix of MVFR and VFR cigs. With afternoon heating, expect cloud cover to gradually diminish with clearing skies though the afternoon.

High pressure arrives tonight, providing clear skies and light winds. Fog may develop early Wednesday morning, with vis as low as LIFR. The most likely locations for vis reductions are HIB, DLH and HYR. There is also a potential for frost, which could limit fog development. The better chances for frost will be INL and locations northwest of HIB. Fog will lift early, with winds remaining light and variable through the end of the taf period.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 257 AM CDT Tue Sep 15 2026

Surface low pressure over southeast Manitoba will quickly move to near James Bay by this evening. Winds will veer westerly and perhaps northwesterly and are expected to strengthen through late morning into early afternoon. Gales of 35 to 45 kts begin to develop by 12Z (7 AM CDT) and will persist through early afternoon. Winds and waves will quickly diminish this afternoon into early evening. Small Craft Advisories and Gale Warnings are in effect for much of today. It is likely there will be a short period of time late Tuesday afternoon into early evening when Small Craft Advisories will be needed after the Gale Warnings end. Winds and waves will become light Tuesday night and persist at 15 knots or less for Wednesday and Thursday. Another storm system will move through the region Friday and Saturday which will bring another period of stronger winds and higher waves.

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

FIRE WEATHER

Issued at 236 PM CDT Tue Sep 15 2026

Fire weather concerns remain low through the forecast. Widespread wetting rain occurred Monday. Minimum relative humidity values will generally stay above 45 percent through the week. After breezy west winds today, light and variable winds are expected Wednesday as high pressure slides across the region. Winds remain light through the week, with scattered rain chances Wednesday night, with rainfall totals less than one tenth of an inch. More widespread rain is possible Friday into 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...Small Craft Advisory until 4 PM CDT this afternoon for LSZ121. Gale Warning until 4 PM CDT this afternoon for LSZ140>148-150.