textproduct: Marquette

KEY MESSAGES

- Temperatures drop back into the 60s today and cool to near seasonal normal values in the upper 50s to low 60s through the weekend. Lows will dip near or below freezing in interior parts of the UP for the next few nights.

- Breezy conditions are expected today and Friday as winds shift out of the west-northwest behind a cold front. Gusts of 30+ mph are likely near Lake Superior from the Keweenaw east to Whitefish Point.

- Another system passing through the region this weekend brings additional rain chances late Saturday into early Sunday.

DISCUSSION

Issued at 330 AM EDT Thu Oct 1 2026

GOES infrared satellite imagery revels extensive cloud cover spreading across Upper Michigan early this morning, associated with a plume of rich mid level moisture which extends northeastward into the Great Lakes from a deep trough and surface low lifting into the southern Plains. Precipitation associated with this system remains well south of the UP this morning over Wisconsin and Lower Michigan. Meanwhile, another deep low pressure system is located well to the north over Hudson Bay, with a cold front extending southwestward. Surface analysis places this feature on the doorstep of Lake Superior and the western UP as of 3 AM EDT Thursday. Ahead of the front, overnight temperatures are quite warm across the area given a persistent weak warm advection regime and insulating cloud cover, with most locations remaining in the upper 50s to low 60s as of this writing.

The surface cold front will sweep across the UP later this morning and bring a quick shift to breezy west-northwest winds in its wake this afternoon. Daytime highs will struggle to get out of the mid 60s across most of the area today as 850 mb temps plummet from 12-13 C this morning to around 5 C by this afternoon. Can't rule out a few rain showers towards Menominee County and the northern shores of Lake Michigan today, but expect dry weather across most of the UP as precipitation associated with the southern stream system remains south of the area. Could see some limited fire weather concerns develop across interior locations this afternoon as dewpoints mix out efficiently and yield RH values in the low 30s as winds gust to 15-20 mph. Even breezier conditions are likely near Lake Superior where guidance still shows a high probability of wind gusts of 30+ mph from the Keweenaw eastward along the shoreline.

Temperatures will be markedly colder tonight as cold advection takes hold and skies clear behind the departing front. While continued windy conditions will likely keep lows from truly dropping off the table, still expect widespread temps in the 30s away from Lake Superior, potentially reaching freezing in a few of the colder spots in the interior. Breezy conditions continue into Friday as CAA regime continues and high pressure building in from the west provides an isallobaric push. Will likely maintain limited fire weather concerns into the afternoon as RH values once again drop to around 30%, though temperatures will be a bit cooler in the 50s. Will also need to consider some lake effect rain showers in the east as 850 mb temps drop to around -5 C while lake surface temperatures continue to reside around 13-16 C. Temperatures really drop off on Friday night as high pressure moves directly overhead and brings an end to the breezy conditions, allowing for optimal radiational cooling. Could see a hard freeze for many interior locations as temperatures drop into the 20s, with areas near the lakeshores likely remaining in the mid to upper 30s. Highs rebound slightly into the low 60s during the day on Saturday. A low passing north of Lake Superior then brings another chance for widespread rain late Saturday into Sunday morning, but rain amounts look to be rather unimpressive again as NBM probs for even a tenth of an inch only site at 25-35% across most of the area, higher in the far east. High pressure then returns for the early part of next week.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 743 AM EDT Thu Oct 1 2026

Various flight categories are present this morning at each TAF site with CMX sporting IFR cigs over the last hour. Observations reveal a cold front working across the western UP and drier air / clearing skies slowly working into the far western lake. Thus, VFR skies should be the primary category by the late morning. Otherwise, the main aviation hazard will be gusty NW winds behind the frontal boundary. Gusts 15-25 kts with occasional 25-30 kts will be common today.

MARINE

Issued at 330 AM EDT Thu Oct 1 2026

Lake Superior: Current south-southwest winds around 15 kt will give way to stronger westerlies today as a cold front crosses the lake this morning, producing 20-25 kt winds across much of the lake and a few gusts to 30 kt from the Keweenaw eastward towards Whitefish Point. West-northwest winds persist into Friday aided by strong cold air advection and pressure rises as high pressure builds in from the west. Gale probabilities have ticked up to 40-50% across the eastern half on Friday, but will hold at small craft headlines over the nearshores for the time being. Wave heights build from 3-5 ft this afternoon to 5-8 ft across the eastern half by Friday. Winds come down Friday night into early Saturday as high pressure moves overhead, but another system passing north of the lake brings 15-25 kt southerlies by later in the day on Saturday, with gale chances increasing again on Sunday in the west-northwesterly cold advection regime in the wake of the system.

Northern Green Bay and northwestern Lake Michigan: 10-15 kt southwest winds go northwesterly at 15-20 kt behind a passing cold front later this afternoon, continuing into Friday. Winds go light as high pressure arrives Friday night into Saturday morning, but another system passing to the north brings stronger southerlies potentially increasing to 20-25 kt with wave heights building to 2-4 ft on Saturday afternoon. Winds shift westerly again at 15-20 kt in the wake of the system on Sunday.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... None. Lake Michigan... None.