textproduct: Marquette

KEY MESSAGES

- Patchy dense fog across the eastern U.P. this morning.

- Mostly dry weather today, then scattered light rain showers return tonight, continuing into Sunday.

- A period of cooler weather in the 40s to low 50s is expected Monday and Tuesday, then 50s for highs and 30s to low 40s for lows into next weekend.

- Tuesday starts off a more active period with almost daily chances for rain into next weekend.

DISCUSSION

Issued at 306 AM EDT Sat Oct 24 2026

Early morning GOES WV imagery and RAP analysis show the strong upper ridge over the Southern Plains extending up to northern Ontario with split flow troughing upstream to the west. The southern trough is over the southwest CONUS and the northern one is over the Canadian Prairie, supporting the sfc low near Lake Winnipeg at 996 mb. 1030 mb high pressure over New England sandwiches the UP in a tightening pressure gradient today as the low continues lifting north, increasing WAA from south to southwest flow. Mostly cloudy skies have taken over and radar reflectivities suggest spotty showers or sprinkles are attempting to graze the western UP. Dry air in place means little, if any accumulation, will become of this. Patchy dense fog has been observed in the east, but opted to hold off on any products given the increasing insulating cloud cover, transient nature of the fog, an strengthening winds. Temps warm from the mid 40s to mid 50s this morning to the 60s to mid 70s today, warmest west and in downslope flow. Winds continue to increase during this period as well, reaching 10-15 mph with gusts of 20-30 mph, strongest near the central Lake Superior shores as well as other areas of south downslope flow where gusts up to 35 mph are likely (50-60% chance). Cloudy and dry weather persists until tonight when scattered rain showers return from the west with a cold front. As these showers slowly progress eastward tonight, temps settle into the 40s to low 50s.

Showers linger through Sunday morning over the east, becoming more isolated in the afternoon as drier air presses in and the front continues to the southeast. Rainfall totals will be 0.1 inch or less. Westerly winds behind the cold front bring cooler, closer to normal temps peaking in the 50s to low 60s, coldest northwest and warmest in the south-central UP. Better breaks in the clouds in the afternoon hours as well as much drier Tds in the 20s in the west support RH falling into the mid 20 to mid 30s interior west. Higher minimum RH in the upper 30s to mid 60s is expected in the Keweenaw and east. Thankfully, winds gusts remain under 15 mph where RH is lowest with less than a 15% chance of gusts above 20 mph with RH below 30% anywhere in the UP, limiting fire weather concerns.

High pressure passes east over Ontario and the Great lakes Monday and Tuesday. Then flow aloft turns more zonal as the strong ridge in the south gives in, allowing for multiple shortwave troughs to track east next week into the following weekend. The first wave lifts north over the Dakotas Monday night through Tuesday, supporting a weak low to the west which yields light rain over the west half of the UP Tuesday and Tuesday night. This quickly is followed up by a more vigorous shortwave moving over the same area, sending another sfc low to the west of the CWA, keeping shower chances in the forecast through Wednesday night. Discrepancies remain on exact track, but best rain chances (40-70%) are over the west during both events. Guidance quickly begins to struggle after Thursday, but a more active period is anticipated to continue into early November captured by the CPC's 6-10 precipitation outlook of slightly above normal precip.

Otherwise, temps return near normal in the wake of the cold front on Sunday peaking in the 40s to low 50s Monday and Tuesday. Lows Sunday night and monday night are expected in the upper 20s to low 40s. Southerly flow returning for Wednesday and Thursday warm temps into the 50s to low 60s with lows in the mid 30s and mid 40s.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 749 AM EDT Sat Oct 24 2026

An incoming shortwave is bringing about VFR high cloud cover to the UP and another round of pesky fog across the S and E extending as far as SAW. As per usual, VLIFR fog at SAW should lift between 13- 15z and VFR conditions are expected through the majority of the TAF period. Gusty southerly winds will be the rule at all TAF sites today, gusting between 15-25 kts through the late morning to early afternoon. Tonight, a cold front progresses across the UP kicking off light scattered showers and potentially MVFR cigs at all sites while veering winds to the W/WNW. Have opted to include prob30s for -shra largely after 00z.

MARINE

Issued at 306 AM EDT Sat Oct 24 2026

Lake Superior: South winds increase through this morning to 15-25 kts with gusts of 20-30 kts as the pressure gradient tightens overhead courtesy of a low to the northwest and high pressure over New England. Warm southerly flow over the cooler waters creates a more stable airmass, limiting stronger mixing. Isolated gale force gusts to 35 kts are possible this afternoon and evening (10-40% chance over the east), but no Gale Warning will be issued given the expected stability and low probabilities of occurrence. Significant wave heights of 3-7 ft are expected this afternoon into tonight, highest over the northern waters east of the Keweenaw. Winds become westerly 10-15 kts with gusts to 20 kts tonight behind the cold front, increasing on Sunday to 15-20 kts with gusts mainly of 20-25 kts except to 30 kts near the Keweenaw. Winds veer north Sunday night between 15-25 kts before becoming light on Monday with passing high pressure. Winds remain below 20 kts across most of the lake Tuesday with the exception of the Duluth harbor where northeast gusts around 20-25 kts are likely as high pressure departs and a low lifts to the west. Another low quickly follows it over a similar track Tuesday night into Wednesday, resulting in a period of southerly winds 15-30 kts, strongest over the east. West winds behind an associated cold front bring the next potential for gales 20-40% chance.

Northern Lake Michigan and northern Bay of Green Bay: Southerly winds increase this morning to 15 kts with gusts of 20-25 kts for this afternoon and evening. Significant wave heights rise to 2-3 ft in the Bay and 4-5 ft in the northern lake by this evening. Winds fall back below 20 kts into Sunday while shifting to the west, with wave heights falling below a foot in the bay and to around 2 ft over northern Lake Michigan. Light winds persist into early next week, turning northerly Monday and then easterly Tuesday. South winds on Wednesday increase to 15 kts with gusts of 20-25 kts, settling below 20 kts by Thursday out of the west.

MQT WATCHES/WARNINGS/ADVISORIES

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