textproduct: Marquette

KEY MESSAGES

- Rain showers and thunderstorms develop this afternoon north-central and east.

- Additional rain showers and thunderstorms are expected to move into Upper Michigan tonight. Showers and thunderstorms may redevelop by Saturday afternoon across the east.

- Cooler and generally more pleasant weather begins Sunday. Daily chances for rain return Tuesday.

DISCUSSION

Issued at 327 AM EDT Fri Jun 12 2026

Rain showers have more or less exited the region in the past two hours. Evening rainfall associated with a vigorous shortwave pressing through the Great Lakes mostly exited the forecast area before 2am, producing widespread 0.5 to 1 inches for central and western Upper Michigan per KMQT precip estimates, with higher amounts in Houghton County. Mild and moist mid-50s have been observed in the wake of the rainfall. If we are able to cool in the next few hours, patchy fog may develop in interior locations by sunrise.

Broad troughing is currently observed across central Canada, with the ongoing shortwave currently being the most pronounced mid-level shortwave. Today and through the early Monday, upper level low within the trough will slowly migrate from northeast Manitoba to the Ontario/Quebec boarder along Hudson and James Bay. Multiple shortwaves will spin through the base of this feature in the period alongside, several surface fronts/troughs. The first weak wave moving through the forecast comes this afternoon/evening. Daytime instability is expected to peak between 500-1000j/kg across north- central and eastern Upper Michigan ahead of a weak surface trough that will help focus shower and thunderstorm activity. Another wave, supported by mid-level isentropic ascent and a nocturnal LLJ, will allow upstream shower/thunderstorm activity to move across the southern two thirds of Upper Michigan overnight tonight. Severe weather is not anticipated with either wave, but PWATs increasing to near 1-1.5 overnight with the aforementioned forcing may support pockets of moderate rainfall. Outside of these waves today and tonight, breezy 25-35 mph winds are anticipated for the western half of Upper Michigan today thanks to daytime mixing and stronger winds aloft. Model soundings at KCMX suggest potentially tapping into a core of 50kts near 10k feet; while the magnitude appears to be an anomaly, the mixing is present in many of the CAMS. These elevated winds will also support dangerous swimming conditions for the beaches east of Manistique this morning. Given this risk, opted to hoist a Beach Hazard Statement through 18z for Schoolcraft County.

Cold front will eventually move through Saturday, with increasing instability and deep layer sheer peaking 50-60kts ahead of the boundary supporting scattered shower/thunderstorm activity by Saturday afternoon across eastern Upper Michigan. Should an organized storm get going, stronger winds and small hail may be realized. Airmass behind the cold front will support -1 to +2C 850mb temperatures. This cooler airmass will remain over the region into early next week, supporting highs in the 60s to low 70s through at least Tuesday, with overnight lows falling into the low to mid 40s Saturday night through at least Tuesday night. Diurnally forced showers may develop Sunday thanks to this cooler airmass aloft, but probability is currently low (<25% chance). The next rainfall opportunity comes Tuesday/Tuesday night, when another pronounced shortwave digs through the Northern Tier into the Great Lakes. Afterwards, there are indications that a vigorous wave and widespread moderate to heavy rainfall event could move into the Great Lakes region Wednesday night into Thursday.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 135 AM EDT Fri Jun 12 2026

With an eastward shift in rain axis and diminished shower activity over the Upper Peninsula over the past hour or so, save for light rain observed over the east and a few showers moving through the central. One of these may move over KSAW in the next hour or two; otherwise, probability of shower activity at terminals overnight is low - a prob30 was introduced at KCMX where probability is greatest. VFR conditions are expected at KIWD through the period. If a shower develops near KCMX, then MVFR/IFR may be realized; otherwise VFR is expected. KSAW may dip to IFR briefly; otherwise ongoing MVFR will improved to VFR by sunrise. Westerly winds will increase today, with gusts up to 25 kts at both IWD and SAW and into the 35 to 40 kt range at CMX.

MARINE

Issued at 327 AM EDT Fri Jun 12 2026

Rain shower activity has exited the US waters of Lake Superior, save for near Whitefish Point. Suspect pockets of fog may develop across the eastern lake tonight, but elevated winds in the 20-30kt range should limit widespread development. Today, winds are expected to settle over the east half with increasing winds anticipated over northern and western Lake Superior. Near 30kt southwest to westerly winds are expected by afternoon in the wake of a surface trough moving through Lake Superior. Ahead of the trough, thunderstorms may develop along the eastern Lake Superior lakeshores. Winds settle overnight, but are expected to increase again to near 30kts between the Keweenaw and Isle Royale by Saturday morning ahead of a cold front moving through the region. After the frontal passage, winds settle to near 20kts through midweek; although daytime winds may increase to near 25 kts near the lakeshores Sunday afternoon.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Beach Hazards Statement until 2 PM EDT this afternoon for MIZ014.

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