textproduct: Marquette

KEY MESSAGES

- Mainly dry weather persists through Monday with high pressure over the area.

- High temperatures trend slightly upward into the upper 60s to low 70s through the end of the week.

- A few rain showers may graze the western UP this weekend, but more widespread chances for rainfall hold off until Tuesday next week.

DISCUSSION

Issued at 127 PM EDT Thu Sep 24 2026

Early this afternoon 500mb model height analysis and GOES satellite water vapor imagery showed ridging over the south-central U.S., centered over SE TX with the northern extent of the ridge up through the Great Lakes and into western Quebec. A shortwave was moving through northern MN spreading cirrus clouds into the western U.P. Winds were light from the southeast and temperatures had recovered quite well, into the 60s, for much of the U.P. Scattered fair weather cumulus had formed with daytime heating over the western U.P. and also over the east, near Lake Michigan.

Ridging will be in place through the weekend over the south-central U.S. and will continue to extend northwards into the Upper Great Lakes, with an omega like blocking pattern tonight through Saturday. LREF ensembles are showing a rapid weaking in 500mb positive height anomalies early next week with troughing developing over central Canada and into the central U.S. This will bring a shift from the warm, dry weather to cooler weather along with the chance for precipitation next Tuesday and Wednesday.

Through the weekend, the blocking ridge and an extensive surface high pressure will continue to bring dry weather with slightly above normal daytime temperatures (highs in the 60s to low 70s) and seasonably cool nights (lows in the 40s, with upper 30s over the interior). Winds will also be light with a weak pressure gradient over the region. A few disturbances will ride the western edge of the upper level ridge bringing precipitation close to the U.P. at times but likely remaining west of the area. A period of cloudiness can be expected tonight as the first disturbance pushes north through MN. Skies will clear again during the afternoon Friday with additional cloudiness expected over the far west for the weekend, while the central and east remain under clear to partly cloudy skies. Fog formation is less likely tonight as high clouds should keep temperatures from bottoming out as much as the previous nights.

Additional shortwaves will move around the western edge of the ridge this weekend bringing clouds into the far west. However, expecting the deeper moisture to stay west of the U.P. with only and outside chance (<15%) for light showers to impact the far west Saturday night.

Late in the extended forecast, Tuesday into Wednesday, probabilities for more appreciable precipitation begin to increase. LREF is indicating a 50% chance for 0.5" or more of rainfall in the far west, with lesser chances (30%) in the far east. There is still a lot of uncertainty with the evolution of the system including the track and strength, with drier solutions showing a low or open wave tracking north of Lake Superior with shorter duration precipitation as the cold front swings through the U.P. Wetter solutions show a stronger surface low tracking across the U.P. but these wetter solution are outliers at this time.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 143 PM EDT Thu Sep 24 2026

With TAF sites under a prolonged period of high pressure, VFR will be the predominant flight category. Therefore, focus turns to any visibility restrictions again tomorrow morning due to fog formation. For now, will only carry MVFR/IFR mention at SAW where probabilities are at least 25% and winds are especially light.

MARINE

Issued at 127 PM EDT Thu Sep 24 2026

For Lake Superior: Hazardous marine conditions are not expected through Monday. High pressure will bring light winds of 15kt or less, mainly from the east and southeast through Saturday, shifting more southerly on Sunday into Monday. A storm system could impact the area Tuesday into Wednesday with cold air advection and a tighter pressure gradient promoting gusty northerly winds. Plenty of uncertainty remains, current probabilities for gales Tuesday into Wednesday are 25-45%, mainly over the eastern half of the lake.

For the Bay of Green Bay and Northern Lake Michigan: Hazardous marine conditions are not expected through Monday. Expect light winds, 10kt or less, through the weekend with winds mainly from the south-southeast.A storm system could impact the area Tuesday into Wednesday. Plenty of uncertainty remains, current probabilities for gales Tuesday night into Wednesday are 5-15%, mainly over the northern Lake Michigan.

MQT WATCHES/WARNINGS/ADVISORIES

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