textproduct: Duluth

KEY MESSAGES

- Isolated to widely scattered showers and storms with a cold front this afternoon and evening. A few of these storms may become strong, capable of producing wind gusts of 40 mph, small hail, and locally heavy downpours, with the best potential in east-central Minnesota into northwest Wisconsin. - Strong west-northwest winds are very likely on Wednesday, with gusts of 30 to 40 mph forecast, strongest in the Minnesota Arrowhead.

- Additional precipitation chances arrive late this week into the weekend. There is a slight risk (level 2 out of 5) for strong to severe thunderstorms Friday afternoon and evening.

- A pattern change to noticeably cooler temperatures is favored this weekend into early next week.

DISCUSSION

Issued at 240 PM CDT Tue Sep 8 2026

Rest of Today - Tonight:

As of 230 PM this afternoon, regional satellite imagery shows much of the Northland under cloud cover ahead of a cold front now moving into portions of central to north-central Minnesota, with rapid clearing behind it. This extensive cloud cover has kept much of the area capped to thunderstorm development so far today aside from a few scattered showers/non-severe storms that have been moving through north-central Minnesota. CAMs continue to be fairly reserved regarding additional scattered shower and thunderstorm development along the cold front later this afternoon and evening as it propagates east across the area as the cloud cover makes it difficult to break through low-level capping in addition to drier air moving in aloft. If the capping inversion were to break, then there is potential for a few strong storms to develop mainly in east-central Minnesota to northwest Wisconsin in the 4 PM - 9 PM timeframe and access 800-1500 J/kg of MLCAPE amid 40-50 kt of a fairly unidirectional effective shear profile. Storm intensity and coverage would then wane around and after sunset in northwest Wisconsin. The hazards with any strong storms would be hail up to penny size, wind gusts to 40 mph, and locally heavy downpours.

Lingering moisture in the lowest-levels of the atmosphere behind the cold front tonight in northwest Wisconsin should lead to patchy fog as winds become light.

Wednesday - Thursday:

While the cold front will be east of the Northland on Wednesday and surface high pressure will be slowly building in for mid- week, cyclonic flow and some lingering low-level moisture could lead to some sprinkles or very light rain showers (10-20% chance) north of the Iron Range and into the Arrowhead daytime Wednesday. Little to no accumulations expected. Wednesday will also see very strong daytime west-northwest winds with gusts of 25-40 mph, being strongest in the Arrowhead, particularly in the higher terrain of the North Shore. Probabilities for >45 mph wind gusts continue to decrease, so don't anticipate any need for a Wind Advisory. Expect a near-seasonal day for high temperatures on Wednesday, ranging from the upper 60s to mid 70s. Low temperatures become cooler Wednesday night into the 40s, though the typical cold spots could touch the upper 30s under clear skies and light winds.

Less windy southwest winds and a dry forecast are in store for Thursday under clear to mostly clear skies and high temperatures ranging from around 70 degrees into the upper 70s.

Friday - This Weekend:

We see a couple rounds of precipitation chances return for Friday into this weekend. The first round would be with a surface low ejecting out of the northern Plains daytime Friday and through northern Minnesota Friday PM into early Saturday morning. Strong warm/moist advection with this system in combination with strong synoptic forcing for ascent driven by a strong mid/upper-level shortwave trough and jet could set the stage for isolated to scattered strong to severe storms Friday afternoon and evening when the best instability/strong shear combination would overlap. Still some question as to how far north the warm-sector of this low pressure system would make it into the Northland depending on the forecast ensemble low tracks. As of now, the portion of the Northland with the best potential for strong to severe storms would be along/south of US-2 in northeast Minnesota into far northwest Wisconsin. Storm intensities should wane towards Friday night, with showers/remnant non-severe storms ending west to east into early Saturday morning.

Additional showers and perhaps a few general storms are possible (10-30% chance) on Sunday with weak troughing moving though largely zonal flow aloft, but instability will be limited at best, so likely to be mainly just showers.

We also see the shift to a cooler pattern starting this weekend with high temperatures in the low 60s to low 70s on Saturday and 60s on Sunday. Lows Saturday and Sunday nights could even touch the upper 30s to mid 40s, though the typical cold spots could see mid-30s even! For now, the potential for areas of frost remains less than 20%.

Early Next Week:

The cool pattern persists into early next week with highs in the 60s and possibly even some upper 50s on Monday, with nightly lows in the upper 30s to 40s. Global ensemble members and deterministic models show fairly good agreement on a more robust, Colorado low-type system developing in the lee of the Rockies as a deeper mid/upper-level trough moves across the High Plains into Upper Midwest Sunday night through Monday night. This would bring a good shot at more widespread rain and appreciable rainfall amounts should the forecast system track hold over the next several days.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 109 PM CDT Tue Sep 8 2026

MVFR to IFR ceilings ahead of an eastward-moving cold front this afternoon quickly improve to VFR under clearing skies behind the front later this afternoon and evening from west to east. As the front moves through this afternoon and evening, there remains a low chance for additional isolated to scattered showers and thunderstorms along the front, particularly in east-central Minnesota to northwest Wisconsin. Have included PROB30 mention at HYR for now as confidence in direct thunderstorm impact to the terminal remains low with this update. Can't rule out some fog development in northwest Wisconsin tonight into early Wednesday morning, but have kept IFR or lower conditions out of the HYR TAF for now due to low confidence.

Strong southwest winds of 20-25 kts develop this afternoon into early evening, with gusts briefly dropping off tonight before becoming even stronger out of the west-northwest daytime Wednesday. Can't rule out a few light showers or sprinkles Wednesday morning at INL and into the Minnesota Arrowhead for late Wednesday morning into afternoon.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 240 PM CDT Tue Sep 8 2026

South to southwest wind gusts of 15-25 kt with localized pockets of 30 kt near Saxon Harbor and Grand Marais to Grand Portage continue into tonight. Small Craft Advisories are in effect. Widespread gale potential on Wednesday has backed off for portions of western Lake Superior. Have held onto a Gale Watch from the Outer Apostles to Saxon Harbor and Grand Marais to Grand Portage where gusts of 30-35 kt are most likely (around 50%), with Small Craft Advisories for west-southwesterly wind gusts up to 25-30 kt elsewhere. Winds are expected to weaken out of the west Wednesday night as high pressure moves in, though portions of the North Shore could see gusts to 15 to locally 25 kt on Thursday afternoon, mainly near Grand Portage. Expect additional potential for conditions hazardous to small craft on a more widespread basis in western Lake Superior on Friday and Saturday.

A few non-severe thunderstorms are possible early this evening near the head of the Lake, with occasional cloud-to-water lightning as the main threat. Additional thunderstorm potential arrives Friday afternoon into Friday night, some of which could be strong to severe.

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

FIRE WEATHER

Issued at 240 PM CDT Tue Sep 8 2026

A few showers and storms remain possible along an eastward moving cold front this afternoon and evening. In the Arrowhead, storms are not expected to be strong or severe. However, a few strong storms are possible in the east-central Minnesota to northwest Wisconsin locations between 4 PM to 9 PM this evening, with small hail, erratic wind gusts to 40 mph, and locally heavy downpours possible. Precipitation ends late this evening. Outside of convection, strong southwesterly winds of 20-25mph persist to around sunset and then diminish this evening and tonight as a nighttime inversion sets up.

Strong west-northwest winds arrive for daytime Wednesday, with gusts of 25-40 mph expected. The strongest winds are expected in the higher terrain of the Arrowhead. Lingering low-level moisture will keep min RH at or above 40%, and some sprinkles or even very light rain showers are possible daytime Wednesday in far northern Minnesota into the Arrowhead. Winds ease Wednesday evening as high pressure builds into the area. Lighter southwest winds are in store for Thursday, though afternoon gusts of 10-15 mph are expected. Thursday will be rain-free and sunny with min RH dipping into the mid 30s to mid 40s (%), lowest in northwest Wisconsin.

Friday and Saturday will be windier again, though humidity will be on the increase as shower and thunderstorm chances return Friday afternoon into early Saturday morning. Isolated to scattered strong to severe thunderstorms will also be possible Friday afternoon and evening, with the best potential along and south of US-2 in Minnesota to far northwestern Wisconsin.

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 7 AM CDT Wednesday for LSZ121-140- 147-148-150. Gale Watch from Wednesday morning through Wednesday afternoon for LSZ121-140-147-148-150. Small Craft Advisory until 7 PM CDT Wednesday for LSZ141>146.