textproduct: Duluth

KEY MESSAGES

- Hazardous marine conditions continue this afternoon across western Lake Superior, before wind and waves diminish this evening and tonight.

- Additional rain chances Wednesday evening/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 Duluth to Bayfield.

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

DISCUSSION

Issued at 213 PM CDT Tue Sep 15 2026

Tonight:

Vertically stacked low system is moving toward Hudson's Bay this afternoon, with some wrap around moisture maintaining scattered to broken skies across the Northland today. Cannot completely rule out a passing light shower or sprinkles, but chances are too low to mention at any given location. For tonight, high pressure arrives from the west, and daytime, breezy winds will diminish. With clearing skies and light winds, temperatures will cool into the upper 30s for most locations north of the Iron Range and across the Arrowhead. Low to mid 40s are expected elsewhere, with upper 40s along the shore line. With this cooling, frost is possible across portions of the area, with the most likely area for these impacts being Koochiching County. A frost advisory has been issued. Further south and east, there is a better chance of fog which would prevent frost from becoming more widespread.

Wednesday - Thursday:

Surface high pressure will quickly slide to the east tomorrow, with zonal flow aloft. A weak shortwave will bring a chance of isolated to scattered showers to the area late tomorrow afternoon into the overnight period. Rainfall amounts will be light, maybe a tenth of an inch. Dry conditions return for Thursday, with temperatures continuing to moderate. Highs will be in the mid 60s to mid 70s. Overnight lows will also be warmer, both Wednesday night and Thursday night, with temperatures remaining above 40F both nights.

Friday - This Weekend:

Another, more widespread, rain event is expect for Friday into Saturday. A system will move out of the Rockies with a surface low strengthening over the central Plains and pushing toward the mid Mississippi River Valley. A warm front will move northward, pushing up against dry air pushing southward from east central Canada. Current guidance suggest the warm front will remain to our south, with strong low level jet riding over the warm front, bringing widespread moderate to heavy rainfall to southern portions of the Northland, mainly Burnett county eastward. The WPC Day 4 Slight Risk area highlights this potential for heavy rainfall. The 19Z 9/14 run of the NBM rainfall amount probabilities have trended southward with the chances for more than 0.5" of rainfall, with a 30-40% chance from Pine County eastward.

Drier conditions are expected for Saturday and Sunday, under northwesterly upper level flow, with rain chances return early next week.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 635 PM CDT Tue Sep 15 2026

Scattered to broken VFR stratocumulus clouds are lingering over the terminals across the area this evening. These should gradually dissipate over the next few hours. High pressure arrives tonight, providing clearing skies and light winds. Fog may develop early Wednesday morning, with visibilities as low as LIFR. The most likely locations for the lowest vis reductions are HIB and DLH, but IFR/MVFR is possible at the remaining terminals as well. Fog will lift early Wednesday morning, with winds remaining light and variable through the end of the taf period.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 213 PM CDT Tue Sep 15 2026

West to northwest winds remain gusty this afternoon over western Lake Superior, with current gusts to 35kts. Winds will gradually diminish through the evening, as high pressure builds into the area. Small Craft Advisories and Gale Warnings remain in effect, and will likely need Small Craft Advisories for a short period this afternoon and early evening after the Gale Warnings end. Winds will persist at 15 knots or less 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 213 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 8 PM CDT this evening for LSZ121- 141>148-150. Small Craft Advisory until 10 PM CDT this evening for LSZ140.