textproduct: Duluth

KEY MESSAGES

- Above normal temperatures through Saturday.

- Next chance of rain (20-40%) is Friday afternoon into Saturday.

- Near-normal temperatures return Sunday.

DISCUSSION

Issued at 121 PM CDT Tue Oct 20 2026

SYNOPTIC:

A complex split-flow regime was found aloft over the North American continent early this afternoon. A cutoff low was positioned off the coast of California with a broad relatively flat ridge farther east across the Canadian Prairies into Ontario. A northern jet stream with several troughs stretched across Canada. The first trough axis of note upstream from the Northland stretched from northwest Manitoba to southern Alberta. A southern jet stream was found over the southwest US along the southern periphery of the cutoff low. An area of low pressure ahead of the northern stream trough was centered over northern Manitoba with a cool front trailing to the southwest over southeast Saskatchewan into eastern Montana. Surface high pressure was situated over the Great Lakes and extended south into the Gulf Coast.

LATE THIS AFTERNOON THROUGH THURSDAY NIGHT:

The northern stream trough propagates eastward across the Canadian Prairies and into northwest Ontario by 12Z Wednesday morning. The surface low pressure and cold front will progress eastward across the Northland Wednesday. Winds will turn northerly and remain relatively light, around 5-10 mph. Temperatures will trend a few degrees cooler over the Borderlands, low 60s, while areas south of a line from Cass Lake to Duluth to Hurley will see temperatures in the upper 60s to low 70s.

Transient surface high pressure will drift eastward across the region Wednesday night and Thursday as an upper-level ridge builds over the northern Plains and Canadian Prairies. Temperatures will remain well above normal as winds turn southerly. Lows Thursday morning will range from the low 30s to around 40 degrees. Look for highs in the low 60s to low 70s, about 10-20 degrees above normal. Temps will be cooler for portions of the North Shore and Arrowhead due to on-shore flow. Those readings will be 5-10 degrees above normal with highs in the middle 50s to low 60s.

FRIDAY THROUGH SATURDAY NIGHT:

The Pacific cutoff low will get a slight nudge eastward and is expected to move into the Intermountain West by Friday morning. Surface low pressure is forecast to develop in the Rockies and lift northeastward into Saskatchewan and Manitoba by Saturday morning. A warm front is forecast to lift northward across the Northland for the end of the work week. Isentropic ascent in the warm sector will support a chance of rain showers Friday morning over central and north-central Minnesota and spreading eastward across the Northland through Saturday morning. The highest rain chances will be found near and north of the warm front, mainly over the Iron Range and Borderlands Friday evening. Rain amounts will be meager, less than a tenth of an inch for most areas. A few locations may pick up 0.1-0.2". Temperatures Saturday remain around 15-25 degrees above normal as the Northland stays in the warm sector most of the day. Rain chance end from west to east Saturday and Saturday night.

SUNDAY THROUGH NEXT TUESDAY:

Split flow aloft will persist into early next week. The northern stream will transition toward northwest flow as high pressure drifts eastward across the region. The northwesterly flow will bring cooler air aloft into the region. Cooler, near- normal, temperatures are expected Sunday through next Tuesday. Highs will be in the mid 40s to low 50s. The high pressure over the region will keep precipitation chances low to zero.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 639 PM CDT Tue Oct 20 2026

An upper-level shortwave with a cool front will pass through this evening into tonight. Winds will be light and variable at the surface, but expect a period of LLWS at DLH/HIB/INL this evening into tonight, ending by around 08z. There is a <10% chance for some fog tonight. Did not include this in the TAFs because we have a dry air mass in place. Into Wednesday, expect winds to become more northerly to northeasterly with light speeds. VFR conditions are expected through the period.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 1241 PM CDT Tue Oct 20 2026

High pressure will slowly drift to the east through Wednesday. A weak cool front will advance southeastward across western Lake Superior Wednesday and will be marked with a wind shift. Wind speeds will be in the 5 to 10 knot range for most locations. Waves will generally be less than 3 feet. Northeast winds strengthen Thursday. Wind speeds of 5-15 knots are expected. Gusts of 15-20 knots are possible in the southwest arm of Lake Superior near the Twin Ports. Small Craft Advisories may be needed if wind speeds and wave heights increase with later forecasts. A stronger system will move across the region Friday night and Saturday. Wind gusts and wave heights will become hazardous for smaller vessels as early as Friday evening and may remain strong through Saturday and into Sunday. Small Craft Advisories will likely be needed during that time.

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

FIRE WEATHER

Issued at 1241 PM CDT Tue Oct 20 2026

Surface high pressure drifts eastward tonight and Wednesday as a weak cool front advances southeastward across Minnesota. The front may bring a small increase in cloud cover. Otherwise expect temperatures a few degrees cooler for Wednesday with RH values in the 40-50% range. Winds will turn northerly or northwesterly behind the front and are expected to be in the 5 to 8 mph range with gusts to around 12 mph possible. Winds turn southerly Thursday as high pressure builds over the Dakotas. Look for temperatures in the low 60s to near 70 degrees, except cooler along the North Shore of Lake Superior due to on-shore winds. Afternoon RH values will bottom out in the 40-55% range. Next chance of rain arrives Friday over central and north- central Minnesota. The accompanying system will move farther east Friday night and Saturday providing a majority of the Northland a chance of rain. Rain chances top out in the 20-40% range. Rain amounts are light, less than a tenth of an inch. Cooler, near- normal, temperatures are forecast Sunday into early next week.

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.