textproduct: Duluth

KEY MESSAGES

- Areas of fog this morning will erode by late morning

- Above average temperatures continue today through Saturday with highs in the 60s and 70s. The exception with be along Lake Superior where onshore flow will keep highs in the 50s and 60s.

- Light rain chances return this afternoon and lingers through Saturday. A few rumbles of thunder will be possible but no severe weather.

- More seasonable temperatures return Sunday and through next week.

DISCUSSION

Issued at 232 AM CDT Fri Oct 23 2026

Current conditions/Today:

Onshore flow mixing with low level moisture has manifested a large stratus deck that engulfs western Lake Superior this morning. This cloud deck continues to emanate from the Lake and has advected inland leading to a Dense Fog Advisory being needed for areas around the Lake and inland portions of Carlton and St. Louis County. Conditions are expected to improve as we head towards mid day and the cloud deck retreats back to the Lake. Due to the presence of this cloud deck we have modified the high temps a bit for the immediate areas around Lake Superior. While most the region will likely see temps in the 70s these areas may struggle to get out of the 50 range. If the fog does retreat much faster than what we currently have in the forecast, expect this areas to climb into the 60s.

The latter half of the day will see a warm front lifting northward through the day. Isentropic lift associated with the moving boundary will be best concentrated across our our western counties this afternoon where we have PoPs of 40-60%. In conjunction with the warm front there will be some added forcing as a shortwave rotates aloft clearing the way of the subsidence aloft. Minimal instability available with the HREF showing a 15% chance of an occasional rumble of thunder. Rain totals will be light as this feature swings southwest to northeast during the overnight hours.

SATURDAY:

On Saturday a mature low pressure system propagates eastward across the northern Canadian Prairies and into far northern Ontario. It's associated cold front will be cruising east across the Northland providing another dose of light rain chances and perhaps a rumble of thunder across the region. MUCAPE increases a bit along the boundary as upper-levels cool and mid-level lapse rates increase to 7C/km. This could lead to some isolated storms at times but not expecting anything severe. Rain chances will quickly taper off west to east through Saturday night as the boundary moves into central WI. Additionally, out ahead of this boundary through the day the strong southerly flow will lead to widespread 70s, our last day of 15-25 degrees above normal for a while.

SUNDAY THRU NEXT THURSDAY:

A return to more seasonable temperatures as surface high pressure settles in behind the exiting cold front. Highs will be in the 40s and 50s with overnight lows dropping below freezing. A more active pattern still looks to be in store for the Northland as we head into next week. The cool and dry air mass will help to shunt much of the activity to our south initially but an upper level low is forecasted to eject out of the Central Rockies Monday through Tuesday. The exact path and timing are still a bit in flux between model runs. But some of the thermodynamics would suggest enough cold air aloft to mix in some snow on the northern fringes of the system. This presently does not look to amount to much aside from "conversational snow."

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1239 AM CDT Fri Oct 23 2026

Low stratus has spread off of Lake Superior, and should continue slowly inland overnight. LIFR/VLIFR conditions have already developed at KDLH, and I expect IFR/LIFR conditions to spread to KHIB around 10z. There is potential for fog at INL as well, and have included TEMPO groups for now. Have left the fog out of KBRD and KHYR for now. Visibility will improve Friday morning, with the low ceilings taking a little longer to scatter out. Rain chances and a small chance of a thunderstorm enter the picture for BRD and INL after 20Z, spreading to the MN terminals after 00z. They do not get to HYR until after 06z.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 232 AM CDT Fri Oct 23 2026

Widespread fog engulfs western Lake Superior. The current advisory runs through 10AM. However, the latest model guidance being ingested suggests that this cloud may stick around until a warm front ushers it out this evening. Winds will stay out of the east and northeast around 5 to 10 knots today. With the aforementioned warm front expect winds to flip to out of the south and increase in speeds. Small Craft Advisories may be needed tonight into Saturday.

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

FIRE WEATHER

Issued at 232 AM CDT Fri Oct 23 2026

No fire weather concerns today or tomorrow. A warm front will be moving in from the south in the late afternoon bringing some light rainfall. Saturday a cold front will pivot across the region brining additional rain chances with some isolated storms possible. Cool and dry air settles in for Sunday when RHs will drop into the 20s and 30s. Winds will be out of the west on Sunday with gusts around 20 mph in the afternoon.

See the Fire Weather Forecast product for a more thorough breakdown of fire weather conditions.

DLH WATCHES/WARNINGS/ADVISORIES

MN...Dense Fog Advisory until 10 AM CDT this morning for MNZ020-021- 037. WI...Dense Fog Advisory until 10 AM CDT this morning for WIZ001>003. MARINE...Dense Fog Advisory until 10 AM CDT this morning for LSZ121- 140>148-150. Dense Fog Advisory until 10 AM CDT this morning for LSZ142.