textproduct: Marquette

KEY MESSAGES

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

- High temperatures come in slightly above average, climbing into the upper 60s to low 70s through early next week.

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

DISCUSSION

Issued at 202 PM EDT Fri Sep 25 2026

Water vapor imagery looks quite impressive this afternoon, showcasing the omega-like blocking pattern over the CONUS with deep midlevel lows off the Mid-Atlantic and the Pacific Northwest and stout ridging over the central CONUS. Will note an embedded shortwave moving over the Plains, which could impacts the UP later this weekend...but more on that later. In the meantime, visible satellite shows mostly sunny skies over the UP, with just some patchy fair weather cumulus. Under sunny skies, temperatures are rising quite nicely into the lower 70s for most. With dewpoints mixing out, much of the interior UP is already seeing RH falling to around 45-50%, though some spots are falling even further to near/below 40%. Still, light winds only peaking at around 5-10mph should limit fire weather concerns. Temperatures quickly fall back into the lower to mid 40s across most of the area tonight, while soundings support a chance for patchy fog into the early morning hours.

High pressure will remain over the Great Lakes through the weekend as the blocking pattern persists over the CONUS. In terms of sensible weather this will more or less maintain the status quo across the UP through early next week, yielding continued dry weather with highs in the upper 60s to low 70s each afternoon. The aforementioned weak shortwave riding the western periphery of the ridge this weekend could bring a few showers to the far western UP late Saturday into Sunday, but NBM continues to cap chances for measurable precipitation around 20-30% near Ironwood. Will need to keep an eye on minimum RH values over the next few days with seasonable warm temps and good afternoon dewpoint mixing, but weak pressure gradient and light winds will continue to limit fire weather concerns.

High pressure finally breaks down Monday into Tuesday, paving the way for more substantive troughing to move into the region during the middle of the week. There is still quite a bit of variability with regards to the details ranging from strength, timing, and orientation of the trough to the potential for a stronger surface low to lift out of the Plains and track close to the area. Despite the model spread, there is broad agreement on more widespread rain returning to the region Tuesday into Wednesday. NBM currently depicts a 30-40% chance for at least a half inch of rain across much of the UP during this time period.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 218 PM EDT Fri Sep 25 2026

Main impacts will be visibility restrictions again in any fog formation early tomorrow morning. With clear skies, light winds, and cooler temps tonight, expect more widespread fog coverage. For now, highlighted MVFR/IFR fog at both CMX and SAW. But, this will likely need to be added to IWD with future TAF issuances and any increased confidence as well as the addition of LIFR if needed. Outside of any fog formation, though, conditions will be VFR under continued high pressure.

MARINE

Issued at 202 PM EDT Fri Sep 25 2026

For Lake Superior: High pressure will bring light winds of 15kt or less through early next week, mainly from the east and southeast through Saturday and then shifting more southerly Sunday into Monday. The exception will be Saturday evening into Sunday morning, when NE winds may gust to around 20kts in the western arm of the lake before shifting southerly and then weakening Sunday morning. 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, and 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. Current probabilities for gales Tuesday night into Wednesday are only around 5-15%, mainly over northern Lake Michigan.

MQT WATCHES/WARNINGS/ADVISORIES

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