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 204 AM CDT Tue Oct 20 2026

A stable omega blocking pattern becomes firmly established across the central United States today, keeping our region under the control of an upper-level ridge. Kept the trend for slightly increased daily maximum temperatures going each day through Thursday. Plentiful sunshine will prevail alongside light southerly breezes. Meanwhile, local lake breezes will develop along the Lake Superior shoreline during the afternoon, keeping coastal areas noticeably cooler and closer to seasonal norms along the North Shore, while interior communities continue to experience unseasonable autumn warmth. The lake breeze is expected to move the most inland on Tuesday and Thursday. There will be a slight ripple in the blocking pattern for tomorrow as a weak cold front and upper level trough crosses the Upper Midwest. Not expecting these features to amount too much aside from a slight increase in clouds for Tuesday night through Wednesday morning before dry air aloft overspreads the region again.

Changes begin on Friday as the persistent omega ridge starts to break down. A closed upper-level low over the Great Basin will eject northeastward toward the Upper Midwest. Cloud cover will steadily increase throughout the day. Rain chances are still on track to arrive Friday afternoon into Saturday, and confidence is higher that precipitation will occur over that time period even if scattered as models are becoming more constant with that timing. Because temperatures ahead of the system remain unseasonably mild, all precipitation will fall strictly as liquid rain.

Scattered light rain showers will linger across the area through Saturday as the trough axis and associated cold front push across the Upper Great Lakes. By Monday, dry conditions return as high pressure rebuilds behind the departing system, accompanied by clearing skies. A significant air mass change behind the cold front will drop temperatures back toward seasonal values for late October.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1241 PM CDT Tue Oct 20 2026

VFR conditions with southerly winds of 5-10 kt and gusts up to 20 kt this afternoon. Winds weaken by early evening. A low pressure system over Manitoba will advance east tonight and Wednesday drawing a cool front southeastward across the Northland. Winds will turn northwesterly behind the front. A low-level jet of 30-40 kt is forecast ahead of the cool front tonight which poses a risk of LLWS at INL. There is a 10% chance of IFR visibility at HIB, BRD, and HYR due to radiational cooling tonight as winds become calm.

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.