textproduct: Marquette

KEY MESSAGES

- High temperatures trend upward through the weekend.

- Next chance for showers and thunderstorms comes with a cold front on Saturday. Can't rule out a strong storm or two, but the probability is low.

- More rain showers and thunderstorms are possible Sunday and Monday, but forecast confidence remains low at this time.

DISCUSSION

Issued at 258 AM EDT Fri Jul 24 2026

Mostly clear skies continue across the area today into this evening as weakening high pressure ridging retreats eastward as a low over northern Canada digs towards far northern Ontario. As the cold front of the low approaches the U.P. today and tonight, expect warm air advection to continue across the area, allowing high temperatures to get into the mid 70s to mid 80s this afternoon. With the weather being nice, today will be the best day to get any outdoor work done over the next few days as rain returns on Saturday...

The cold front descending from central Canada arrives early Saturday morning over the western U.P., moving over the central and eastern U.P. by the late morning to early afternoon hours. With the loss of LLJ support and the frontal boundary weakening as it continues to move southeastward with time, the severe weather chances are trending downward with the front's passage. Nevertheless, a stronger storm or two could be squeaked out as around 500-1000 J/kg of MUCAPE and 0-6 km bulk shear of 30 to 35 knots is expected ahead of an along the dying front. Looking at the latest CAMs, there is now a signal that some convection may pop-up behind the cold front later in the afternoon over mainly the central U.P.; should this more recent solution come into play, then it's possible we could see a small, slightly better severe weather threat mainly for hail and wind. SPC has accounted for the post-frontal convection in their latest Day 2 outlook by highlighting a Marginal Risk for severe weather over mainly the south central U.P. for marginally severe hail and wind (for late in the afternoon to early evening hours). Besides the severe chances (or lack thereof) for Saturday, expect rainfall amounts caused by the cold front's passage and the potential convection behind it to not be all that impressive; the latest REFS only a 10 to 30% chance for a wetting rainfall amount (a quarter inch or greater) for the central and east between 7 PM EDT today and 7 PM EDT Saturday. That being said, the chance is a little better over the eastern U.P., ranging anywhere from 30 to 75% depending on the location.

While isolated showers and storms (25% or less chance) are possible Saturday night, chances increase once again come Sunday as a weak Clipper impulse skirts through the Upper Midwest/Upper Great Lakes. While we can certainly expect warmer temperatures and humid sfc conditions come Sunday (dewpoints may get to around 70F), the placement and track of the impulse hasn't been hammered out among the differing model suites yet given how weak it's predicted to be. Should the shortwave move through Wisconsin instead of the U.P. (or even along the Wisconsin/U.P. border), then Sunday may only have some lake breeze induced convection if anything at all. That being said, if the lake breeze or shortwave impulse is able to force anything up, there will be a some thick sfc-based CAPE to work with by the mid to late afternoon hours as well as abundant shear within the troposphere. Therefore, severe chances on Sunday remain low at this time as they will be highly dependent on the track of the Clipper impulse.

A second and stronger Clipper low digs down into Lake Superior/the U.P. on Monday. Rain chances as well as rainfall amounts are greater with the passage of the Clipper on Monday; the latest NBM has 24- hour rainfall amounts of greater than one quarter inch for Sunday night through Monday at 40 to 50% across the entire Upper Peninsula. Depending on the track of the Clipper, Monday could see the highest chances for severe weather, provided that the low goes through the U.P. or just north of the area and we are impacted by the warm sector; there could be 0-6 km bulk shear in excess of 50 kts and MUCAPE of around 1 to 2 kJ/kg. That being said, the chance for severe weather will be next to zero if the Clipper misses us to the south. So overall, while severe weather is possible with the Clipper come Monday (and chances may even be a little bit better), uncertainty on it remains high at this time given the model spread on the Clipper's track.

As we get behind the Clipper and move into the middle of next week, expect high pressure to build over the central CONUS, traveling eastward and weakening with time as we head towards the end of the forecast period. This synoptic setup could bring us a positively- tilted shortwave low or two from Canada during the middle-to-end of next week. Regardless, after a quick cooldown towards normal temperatures behind the Clipper, expect temperatures to progressively rise once again throughout most of the rest of the week as Gulf air advects back into the Upper Midwest.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 710 AM EDT Fri Jul 24 2026

While VFR conditions are expected to continue throughout the period, a dying cold front could potentially bring -SHRA and -TSRA to the terminals late tonight/early Saturday morning as it moves in. In addition, expect S to SW winds to pick up late this afternoon and evening; while I wouldn't be surprised if some gustier winds of around 20 to 25 kts make down to the sfc for an hour or so here and there, with the nocturnal inversion in place, thinking sustained winds will remain at around 10 kts or slightly higher this evening into Saturday morning over the terminals. Thus, expect to see some low-level turb over the terminals tonight, especially at KCMX where model guidance has wind at 2 kft gusting up to potentially 40 kts.

MARINE

Issued at 258 AM EDT Fri Jul 24 2026

Southwest winds of 20 to 25 knots this morning weaken to below 20 knots after sunrise south of Isle Royale as a weak impulse over northern Ontario continues to flee towards northern Quebec. Nevertheless, with a cold front approaching from the northwest today into this evening, expect winds to begin picking up from the south and southwest early this evening to 20 to potentially even 30 knots across the lake; while certainly not expected, the latest REFS does show up to a 15% chance for low-end gales across the open eastern and western lake tonight ahead of and along the cold front. With the cold front arriving over the western lake tonight, expect some showers and storms to push from west to east across the lake through early Saturday afternoon. While the front will weaken with time, some stronger storms are possible over the western lake late this evening, even as the LLJ support and frontal forcing is lost with time; the severe weather threats, should there be any, are looking to be damaging winds and hail. Behind the front, expect winds to dissipate to 20 knots or less by Saturday afternoon.

Light winds of 20 knots or less are expected to continue through next week, even as a few potential shortwaves and impulses move through or by the area. While there is a low-end (25% or less) chance for thunderstorms on Sunday, somewhat better thunderstorm chances look to come on Monday as a Clipper low potentially makes its way across the lake. While confidence is low at this time, there is a non-zero chance for severe weather come Sunday and an ever-so- slightly-higher non-zero chance for Monday as well. Behind the potential Clipper, expect high pressure building over the central CONUS to keep things a little quieter as we head towards the middle of next week.

MQT WATCHES/WARNINGS/ADVISORIES

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