textproduct: Marquette

KEY MESSAGES

- Seasonable temperatures give way to above normal temperatures and humid conditions this weekend through next week.

- Showers and a few thunderstorms return Saturday P.M., mainly across the south half of the UP. Rainfall amounts <0.25 are expected.

DISCUSSION

Issued at 203 PM EDT Fri Aug 28 2026

Afternoon GOES satellite imagery reveals blossoming diurnal cu across the UP with two distinct lake breezes in the east half. The collision of these two boundaries may be the focal point for a few scattered showers, however, soundings in the east reveal a low-level inverted v below a very shallow moist layer, which is then topped off by a strong mid-level cap, so overall not thinking anything more than a few showers (15-20% chance). Otherwise, pleasant weather continues through the rest of the day with high temps poking into the low to mid 70s, 60s north. tonight, patchy dense fog is possible (40-50% chance) across areas of the interior under mostly clear skies and diminishing winds. Overnight lows fall into the upper 40s to mid 50s.

More widespread precipitation chances return tomorrow PM as midlevel flow becomes more zonal, allowing transient shortwaves to return to the Great Lakes. Isentropic lift ahead of a mid-level shortwave moving through Wisconsin tomorrow will be the forcing mechanism for areas of showers and perhaps a few thunderstorms, mainly across the south half of the UP. NBM probability of widespread wetting rain doesn't give much confidence in mitigating ongoing drought conditions with only a 40-60% chance for amounts >0.25" in the south half, lower in the northern half and Keweenaw. Additionally, CAM guidance isn't in full agreement in the overall placement of precip. RAP/HRRR/RRFS 12z runs place the bulk of rain in WI. Regardless, any rain is welcomed! Additional rounds of showers are possible (25-50%) Sunday PM through Monday as embedded shortwaves within broad southwesterly flow aloft work across the region.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 126 PM EDT Fri Aug 28 2026

VFR conditions prevail for most if not all of the TAF period aside from the following possible exceptions: 1) Fog potential 06-12Z primarily at SAW; TEMPO IFR vsbys to account for this. Probs for IFR fog are < 30% at CMX and IWD, so it was not included in the TAF. 2) Showers are expected to move into IWD toward the end of the TAF period by late Saturday morning or early afternoon, with a medium probability of cigs and/or vsbys falling to MVFR. Otherwise, a wind shift to the NE is likely around 20-21Z at KSAW as the lake breeze moves in, and a brief shower cannot be ruled out as this occurs. Diurnal cu should dissipate this evening.

MARINE

Issued at 203 PM EDT Fri Aug 28 2026

Lake Superior: Light winds remain in place before becoming southerly Saturday. Gusts 15-20 kts may be common Saturday PM in the eastern half of the lake. Winds fall below 15 kts through Sunday, however, W- NW gusts 15-25 kts are expected funneling down the western arm of the lake Sunday night ahead of a low pressure system.

Northern Green Bay and northwestern Lake Michigan: Winds <15 kts hold tonight before southerly winds increase through Saturday, peaking between 20-25 kts Saturday night. Significant wave heights Saturday PM increase between 1.5-3.5 ft, greatest in the open waters of Lake Michigan. Breezy S to SE winds 10-15 kts hold into early next week.

MQT WATCHES/WARNINGS/ADVISORIES

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