textproduct: Duluth

KEY MESSAGES

- Scattered rain showers are expected this afternoon and evening mainly south of a line from Cass Lake to Grand Rapids to Two Harbors. A few rumbles of thunder are possible with the strongest showers.

- A warmup is expected Tuesday with high temps 10-15 degrees above normal. A little cooler through the rest of the week while still on the warm side of normal.

- Sparse rain chances return late this week. A more widespread chance of rain will arrive early next week.

DISCUSSION

Issued at 301 PM CDT Mon Oct 5 2026

SYNOPSIS:

A mid-level ridge was located over the northern Plains and Canadian Prairies this afternoon with a closed upper low over northern Quebec. A shortwave trough was found east of the Rockies from the Nebraska Panhandle to northern Alberta. A second trough was positioned over southern Manitoba and the eastern Dakotas. A broad area of isentropic ascent aloft supported and area of stratus and cumulus clouds over central Minnesota into portions of eastern North Dakota. At the surface developing low pressure was found over central Saskatchewan with a serpentine warm front which extended south over eastern Montana and southwest North Dakota then east across northern South Dakota.

TONIGHT:

The surface warm front will lift northeastward across Minnesota and northwest Wisconsin by 7 AM Tuesday as the shortwave troughs propagate eastward. Persistent isentropic ascent north of the warm front will support scattered shower development over west-central Minnesota initially expanding and moving eastward into central and portions of northeast Minnesota by this evening. 05.18Z RAP analysis reveals a bubble of <= 700 J/kg of MUCAPE over southeast North Dakota and west-central Minnesota. That area of meager instability will propagate northeastward across central and portions of northeast Minnesota this afternoon and evening. A few weak thunderstorms are possible in that area. A 25-35 kt south-southwesterly low-level jet over eastern South Dakota this afternoon will advance northeastward this evening and will strengthen to 25-45 kt overnight. South of the surface warm front momentum transfer may be sufficient to generate wind gusts of 15 to 20 mph over the Brainerd Lakes and east into northwest Wisconsin. Rain amounts from the showers will generally be between a trace and a tenth of an inch. Some spots may pick up as much as two tenths of an inch. Areas along and north of a line from Pine River to Grand Marais will likely stay dry. Showers and perhaps a few storms will move out of northwest Wisconsin Tuesday morning. A few spots in the eastern Arrowhead may see frost develop if skies can remain clear.

TUESDAY AND TUESDAY NIGHT:

Skies will clear from west to east during the day and temperatures will trend warmer in the wake of the warm front. Look for highs Tuesday to reach the middle 60s to middle 70s, around 10-15 degrees above normal. Gusty southerly winds are expected over northwest Wisconsin into the I-35 corridor of Minnesota as the low-level jet gradually weakens and pushes eastward during the day. Gusts of 15-25 mph are expected with the highest values east of a Hayward to Bayfield line.

A cold front will advance southeastward across northern Minnesota into northwest Wisconsin by early Tuesday evening. Winds will veer northwesterly behind the cold front and will gradually weaken during the evening. Low temps will be in the upper 30s to middle 40s.

WEDNESDAY THROUGH FRIDAY NIGHT:

Northwest flow is forecast in the wake of Tuesday's cold front. Temperatures will cool slightly while remaining several degrees above normal. Diurnal shower chances are expected as colder air aloft advects east-southeast over the Northland. Highs will be in the low 60s to near 70 on Wednesday then upper 50s to middle 60s Thursday and Friday.

SATURDAY INTO EARLY NEXT WEEK:

A more unsettled pattern takes shape Saturday into early next week. Guidance indicates an upper-level ridge will move into the northern Plains and Canadian Prairies Friday night and Saturday morning. A low pressure system is forecast to develop over eastern Montana and ride northeastward toward James Bay by Sunday morning. That progression will pull another warm front northward across the region with temperatures climbing well above normal for Saturday. Light rain showers are possible ahead of the front Saturday. A cool front will follow on Sunday and will stall out over the Upper Midwest Sunday night and Monday leaving a baroclinic zone in place across Minnesota and Wisconsin. Widespread shower chances are forecast Sunday through Tuesday.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 625 PM CDT Mon Oct 5 2026

Radar this evening shows some scattered showers moving across north central MN with an occasional lightning strike embedded within this activity. Ceilings remain VFR but visibility reductions from the passing rain will briefly bring flight categories down to MVFR/IFR. This showery activity will continue east and taper off through the overnight hours. A strong low level jet ramps up out of the southeast inducing widespread low level wind shear overnight. The jet will weaken tomorrow morning with southerly winds initially to start the day, however, a cold front marching across the region will bring an abrupt wind shift to out of the northwest for the afternoon.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 301 PM CDT Mon Oct 5 2026

Winds become southerly tonight and veer southwesterly Tuesday. Wind speeds and gusts will increase in response to a warm front lifting northeastward across the lake. The front will be accompanied by scattered rain showers from early this evening through early Tuesday morning. Wind gusts of 20-25 kt are expected for portions of the south shore waters and near Grand Portage. Small Craft Advisories were issued for the locations and times when conditions will be the most hazardous. A cold front will arrive Tuesday evening. Winds will veer northwesterly behind that front and should become gusty again for Wednesday. Another round of Small Craft Advisories will likely be needed. Winds and waves relax early Wednesday morning before increasing again Thursday. A period of stronger winds and more persistent hazardous conditions for small craft will develop Saturday and persist through next Monday.

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

FIRE WEATHER

Issued at 301 PM CDT Mon Oct 5 2026

Light rain showers are likely this afternoon into the evening generally south of a line from Cass Lake to Grand Rapids to Two Harbors including all of northwest Wisconsin. Rainfall amounts up to a tenth or two are possible though lower totals are likely. Warmer Tuesday with south and southwesterly winds of 5-15 mph with gusts of 15-25 mph Winds veer westerly by late afternoon or early evening. Dry conditions and gusty northwest winds are likely behind a cold front on Wednesday. Northwest winds of 10-18 mph with gusts of 20-30 mph are forecast. Afternoon RH values will drop into the 30-45 percent range. Portions of northwest Wisconsin may see RH values below 30 percent. The dry and gusty conditions will cause heightened fire weather conditions. Thursday and Friday appear dry with minimum RH values 30-50 percent though winds won't be as strong. Clouds should increase this weekend into early next week and rain chances return which will limit the afternoon drying potential.

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 from 4 AM to 4 PM CDT Tuesday for LSZ121- 140-148-150. Small Craft Advisory from 10 AM to 4 PM CDT Tuesday for LSZ146- 147.