textproduct: Marquette

KEY MESSAGES

- Patchy dense fog is possible (30-60% chance) late tonight into Sunday morning.

- Widespread rain chances return Monday night. Rainfall amounts between 0.25 and 0.75 inches are likely by Tuesday afternoon.

- Mostly dry and cooler weather the remainder of next week.

DISCUSSION

Issued at 255 PM EDT Sat Apr 25 2026

Fairly quiet and benign weather persists over the weekend as high pressure ridging extends into the Great Lakes from Quebec. Aloft a closed low spins over the Canadian Prairie, sending shortwaves along it's southeast periphery over the Dakotas and MN. This coincides with a frontal boundary which won't make much eastward progression this weekend. The combination yields a low chance (20% chance or less) for light showers grazing the western UP on Sunday. Otherwise patchy fog is possible late tonight into Sunday morning (30-60% chance for vis below 1/4 mile) where there is weak upslope flow, particularly in the Keweenaw, north-central and eastern UP. Highs today range from the 40s to low 50s in the Keweenaw, north-central and east; upper 40s to low 60s elsewhere. Temps settle into the 30s to low 40s overnight. Increasing southerly flow makes Sunday's highs warmer in the 50s at the lakeshores and 60s in the interior. Slightly warmer lows Sunday night in the upper 30s to mid 40s.

Meanwhile a trough over the Pacific approaching CA will make landfall tonight, moving to the Rockies on Sunday and out over the Plains on Monday. There is good model agreement this will develop a CO low late Sunday, which will move out over KS by Monday morning and lift up to WI by Monday night. This is expected to bring the only substantial precipitation in the forecast to the UP Monday night into Tuesday as it moves overhead. Current NBM system total QPF is between 0.25 and 0.75 inches with 45-55% chances for >0.5 inches of rain across much of the CWA. Higher probabilities of >0.5 inches (up to 80%) reside in the south-central UP with lower values (~30%) noted in the far east. Probabilities of exceeding 1 inch are between 10-20% over the west half of the UP with higher values between 25-45% in the south-central UP. This has the potential to result in additional river rises, prolonging river flooding impacts. but not much if any areal flooding is anticipated as instability is not impressive limiting strong thunderstorm potential.

Surface high pressure once again becomes the dominating factor the remainder of the work week and possibly into the weekend, favoring drier weather. Mid level troughing becomes situated over Eastern Canada and the Midwest/Northeast, resulting in a cooler pattern with highs and lows between 5 and 10 degrees below normal; highs in the 40s to mid 50s and lows in the upper 20s to 30s. Medium range guidance struggles to resolve the mid level pattern into the weekend, thus confidence in any future precip chances remains low. That said, the troughing pattern and cooler northerly flow likely persists into May, captured well by the CPC outlooks out to 3-4 weeks showing below normal temps favored in each outlook.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 807 PM EDT Sat Apr 25 2026

Persistent upsloping this evening continues to contribute to MVFR cigs at SAW, but IWD and CMX are both holding at VFR. Fog will become widespread at both CMX and SAW tonight with prevailing IFR/LIFR through at least Sun 12Z. At IWD, will trend toward some MVFR visibilities in the Sun 12-18Z time frame for now, but drier air there will mitigate the impacts.

MARINE

Issued at 255 PM EDT Sat Apr 25 2026

High pressure extending overhead keeps winds light and variable through the weekend. Easterly winds increase on Monday to 20-30 kts as low pressure moves to Wisconsin. There are two potential periods of gales as this low moves northeast over Lake Superior. The first period is southeast gales late Monday into Tuesday morning over the east, particularly near the international border waters. Probabilities for gales of at least 35 kts are generally 30-60% over the eastern open water zones, except up to 80% along the international line. How far southwest from the international line the first gales will occur depends on the low pressure track impacting the strength of the low level stability over the water. The second period comes behind a cold front with strong cold air advection and pressure rises yielding westerly gales on Tuesday, strongest winds over the east half of the lake (30-60% chance of gales to at least 35 kts).

MQT WATCHES/WARNINGS/ADVISORIES

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