textproduct: Duluth

KEY MESSAGES

- Areas of dense fog early this morning will impact the morning commute around the Twin Ports.

- Dry conditions today with temperatures near to slightly above normal in the middle 60s to low 70s.

- Periodic shower chances return Saturday, followed by a more organized system bringing a widespread soaking rain Monday night through Tuesday.

UPDATE

Issued at 334 AM CDT Fri Sep 25 2026

Mid and high clouds have cleared from the Twin Ports and vicinity, allowing poor visibilities to develop, especially along the St. Louis River valley between the Twin Ports and Cloquet. Webcams show very poor visibility around Thompson Hill and other nearby areas. Have decided to issue a Dense Fog Advisory for Carlton/South St. Louis and Douglas county zones for now, but I may need to expand it farther into Wisconsin and south along the I-35 corridor as conditions evolve this morning.

DISCUSSION

Issued at 319 AM CDT Fri Sep 25 2026

Stratus is lingering over the Northland early this morning in the wake of yesterday's rainfall. Where the stratus has cleared, we should see some areas of fog, with some locations already experiencing visibilities of a mile or less. Since there is a large area of cleared stratus from the I-35 corridor east through northwest Wisconsin, a Dense Fog Advisory may be needed in this area. This area did not receive much rainfall over the last 24 hours, so the fog is likely to be more patchy in nature.

Upper-level ridging builds over the area today, which should help provide a dry day today. Expect partly to mostly sunny skies, with clouds diminishing through the day. near to slightly above normal high temperatures to range from the mid 60s to the lower 70s. Tonight, quiet conditions continue with light winds, which could once again allow for fog to develop during the overnight hours.

A fast-moving upper level shortwave will approach the region from the west on Saturday, riding over the top of the upper level ridging. This will bring increasing clouds and a chance for rain showers, primarily during the afternoon and night time hours. The highest chances for measurable rainfall will be focused over central and north-central Minnesota, though amounts will be light and generally remain under a tenth of an inch. High temperatures on Saturday will be slightly cooler. Highs will range from the low 60s under the cloud cover to the upper 60s and low 70s elsewhere. The showers will linger into Saturday night before tapering off early Sunday morning. Clouds will then gradually diminish through the day on Sunday, with otherwise dry and mild conditions. Once again, high temperatures should be in the 60s.

For the last couple days we have been eyeing a much more dynamic and large scale weather system expected to impact the Upper Midwest early next week. By Monday, southeasterly winds will increase as a robust area of low pressure begins to take shape over the Plains. The upper level trough associated with this system has been depicted on the ensemble models as moving across the Rockies Monday and Tuesday, then ejecting out across the plains Wednesday. The energy with this is likely to be split between a northern stream and a southern by the time it gets to us, which will affect the timing and precipitation amounts we will receive. Most of the models bring a widespread, soaking rainfall across much of the Northland beginning Monday night and continuing through Tuesday night. Anomalously high moisture surging northward ahead of this system may have a tropical connection, with moisture from the remnants of Polo or Odalys streaming in our direction. This may lead to much needed rainfall totals, with a few rumbles of thunder possible Monday night. Showers will gradually diminish on Wednesday as the system departs to the east, ushering in cooler and drier air. High temperatures will drop into the lower and middle 60s for the middle and latter half of next week.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 618 AM CDT Fri Sep 25 2026

Widespread stratus ranging from LIFR cig/vis for KDLH to MVFR for KHIB and KINL, to VFR at KHYR under clear skies. The stratus is expected to slowly lift today, returning to at least MVFR by 18z, then still further to VFR around 00z. Dense fog which has developed at KDLH early this morning is expected to slowly dissipate and return to VFR by 15z. Fog may develop once again tomorrow night, and have included MVFR visibility for KDLH starting around 09z. MVFR stratus to begin moving to near KBRD by the end of the TAF period, which will spreading northeast after 12z.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 319 AM CDT Fri Sep 25 2026

Quiet conditions are expected on western Lake Superior today and tonight with light northeast winds picking up to 5 to 10 knots and waves remaining at 1 foot or less. Patchy fog may limit visibility early this morning. On Saturday, northeast winds will strengthen to 10 to 15 knots with gusts up to 20 knots, building waves to 1 to 3 feet. Winds veer southerly on Sunday ahead of a stronger system that may bring hazardous conditions for small craft by Tuesday.

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

FIRE WEATHER

Issued at 319 AM CDT Fri Sep 25 2026

No critical fire weather conditions are expected through the weekend. Southerly winds at 5 to 10 mph are forecast for today with afternoon relative humidity values ranging from 50 to 60 percent for northwest Wisconsin, and 60 to 80 percent for northeast Minnesota. Southerly winds will persist through Sunday, though speeds will increase slightly. There will be a chance for rain on Saturday, particularly over central and northern Minnesota. Additional widespread wetting rain is expected early next week. Minimum relative humidity will remain above 40 percent across the entire area through the weekend.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...Dense Fog Advisory until 8 AM CDT this morning for MNZ037. WI...Dense Fog Advisory until 8 AM CDT this morning for WIZ001. MARINE...None.