textproduct: Marquette

KEY MESSAGES

- Well above normal temperatures today with widespread high in the mid to upper 60s.

- A quick hitting system brings widespread light rain to the U.P. tonight into early Thursday. Expect fairly minimal amounts in most locations, with the best chance for a wetting rain over the western UP.

- Expect a cooler and drier end to the work week as temperatures settle back into the mid 40s and 50s for Thursday and Friday.

DISCUSSION

Issued at 215 PM EDT Wed Oct 28 2026

Early afternoon GOES WV imagery and RAP analysis reveal a trough over Manitoba, extending south into the Dakotas with a deeper trough further upstream over the Pacific Northwest. This is supporting two areas of low pressure over western Canada. The southern shortwave moving northeast through this evening from the Dakotas to Northern Ontario quickly shoves a sfc low with it over western Lake Superior before it phases with the low to the northwest. The rest of this afternoon remains dry as warm air advection yields unseasonable temps well above normal (+15-25 F) in the 60s. South winds become breezy by this evening as a 50-60 kt LLJ sets up. Gusts of 20-25 mph are expected with gusts around 30 mph in areas of downslope flow. Favorable dynamics support a quick hitting round of rain showers and thunderstorms with the cold front pressing through. PWATs briefly reach 1 to 1.15 inches, supporting 0.1 to 0.5 inches of rainfall over the west half. Lesser amounts below 0.25 inches are expected in the east, mainly around 0.1 inch as these thunderstorms weaken. Bulk shear will be plenty strong given the aforementioned LLJ, but MUCAPE values struggle to reach 500 J/kg and decrease into tonight. Modest lapse rates could support gusty winds when these arrive in the west should they hold together, but arrival after sunset is not favorable for strong storms to persist. SPC has a marginal risk in the west for damaging winds.

The UP will be in the wake of the cold front Thursday morning as the low moves to Quebec. Expect cooler temps and breezy west winds courtesy of CAA and pressure rises. Gusts in the Keweenaw and near Lake Superior will likely be between 25-35 mph. Temps peak in the upper 40s to upper 50s, coldest northwest. Dry air initially clears skies out early Thursday morning, but colder air begins to result in lake effect clouds. There is a low chance for lake effect rain showers Thursday night in the far east (15-24% chance); any rainfall amounts would be negligible. Temps return to near normal Thursday night in the 20s to mid 30s, coldest interior west. The exception to this is for mid 30s to upper 40s far east where insulating lake effect cloud cover resides.

Cooler and drier weather continues into Friday as surface high pressure moves directly overhead, tapering off winds. Lake effect cloud cover decreases, yielding plenty of sunshine as 850 mb temps warm. High pressure extending overhead through the weekend likely keeps dry weather going (85-90% chance). Temperatures return to the 50s with morning lows warming back to the 40s by the start of next week. Guidance then hints at a stronger system moving out of the Plains and approaching the Great Lakes during the early part of next week, but a lot of variation with respect, to track, timing, and intensity remains. Thus 25-50% PoPS return Monday night and persist the remainder of the forecast.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 159 PM EDT Wed Oct 28 2026

A shortwave will bring a round of rain showers as it passes from west to east this evening, reaching IWD/CMX between ~22-03Z and SAW by 03- 05Z. There is a around a 30% chance that IWD could also see a thunderstorm as this system passes through. MVFR conditions are expected overnight, with conditions improving to VFR during the day on Thursday. Southerly winds with gusts around 25 kts will be seen this evening, with winds expected to become westerly overnight as the system moves through. LLWS will also be present at all sites tonight as the shortwave passes through.

MARINE

Issued at 215 PM EDT Wed Oct 28 2026

Lake Superior: South winds quickly increase tonight to 15-30 kts, strongest over the east half as another low tracks to northern Ontario. A cold front sends a round of rain showers and thunderstorms from west to east this evening into tonight, potentially yielding gusts up to 35 kts at times (30-50% chance). Winds shift westerly behind the cold front for Thursday between 20- 30 kts, strongest over the east half of the lake where cold air advection and pressure rises continue to suggest a 40-60% chance for gale force gusts around 35 kts. Opted again to hold off on a Gale Warning given spatial and duration uncertainty as well as significant discrepancies among probabilistic guidance. Winds diminish below 20 kts from west to east Thursday night into Friday morning as high pressure builds over the region. Winds are expected to remain below 20 kts through early next week with continued high pressure influence. Significant wave heights increase to 3-6 ft by early Thursday morning, then rise further by Thursday afternoon to 4- 8 ft in the west and 6-11 ft in the east. Waves then settle below 4 ft from west to east through Friday morning.

Northern Lake Michigan and northern Bay of Green Bay: Another low passing north of the area tonight increases southerly winds to 20-30 kts through early Thursday morning. Waves increase to around 3-4 ft in the bay and 5-7ft in northern Lake Michigan tonight, settling below 4 ft by Thursday afternoon. Winds shift westerly at 10-15 kts behind a passing cold front on Thursday, with lighter winds then expected this weekend through early next week courtesy of high pressure.

MQT WATCHES/WARNINGS/ADVISORIES

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