textproduct: Marquette

KEY MESSAGES

- Showers and thunderstorms end from west to east by mid morning.

- A dry midweek period will be followed by active weather to wrap up the work week.

- Temperatures run more seasonal for the forecast period.

DISCUSSION

Issued at 310 AM EDT Tue Oct 13 2026

Early this morning, the UP remains on the northern periphery of broader midlevel ridging over the central CONUS, with a subtle shortwave rippling through, while a deepening midlevel low spins over Nevada. At the surface, low pressure is centered over central WI, and associated WAA into the UP has been able to touch off a round of widespread showers and storms. These are moving through the eastern half of the UP, and should largely be out of the area by sunrise. MRMS indicates a widespread 0.25-.50in of rain has fallen so far tonight, with higher embedded totals as high as 0.7-0.9in. This aligns well with available surface observations. Rainfall rates over the area at this time are beginning to fall back, so these higher-end amounts are not looking so likely in the eastern UP, but totals up to a half-inch are possible. Will not rule out some lingering light rainfall into the morning, both in the east as the system slowly pulls away, and over the far west and north-central with upsloping NNE flow. Temperatures currently range in the upper 40s to lower 50s for most, and should only fall back a couple degrees further the rest of tonight. Under cloudy skies and with a cooler airmass gradually sinking in, temperatures only rise as far as the mid and upper 50s across most of the UP. However, the south- central UP should see highs rising into the lower to mid 60s.

Ridging slowly recovers Wednesday, allowing for a return to dry and generally quiet weather through at least early Thursday. It will be otherwise gloomy as skies stay cloudy for most of the day, though more breaks in the clouds are possible into Wednesday night. Temperatures peak in the 50s Wednesday afternoon, then plummet into the lower 30s for most of the UP overnight. The interior-western UP turns even colder, especially if skies can clear partially; expect lows to range in the mid/upper 20s there. Temperatures peak in the mid/upper 50s Thursday, then dry weather finally gives way to rain chances by the evening ahead of a couple approaching systems.

By Thursday, the Nevada low will have moved over the Rockies, with a surface low finally closing off and ejecting out into the Plains by the afternoon. Meanwhile, a Clipper wave will be dropping out of Alberta. Guidance remains in agreement that this clipper will phase with the Colorado low right around 12Z Friday over the Great Lakes, kicking off a quick round of rainfall Thursday evening and night. This may be followed by lingering lake effect rain Friday as 850mb temperatures fall below 0C, with lake surface temperatures still in the lower teens. Meanwhile, surface low pressure rapidly deepens over the Lower Great Lakes, setting up a very tight pressure gradient over the Upper Midwest that results in strengthening northerly winds. Multiple ensembles hint at strongly elevated wind potential during Friday. While the jury's still out on whether or not this pattern will generate storm-force winds over Lake Superior (less over land, but still elevated), the ECMWF, Canadian, and GFS ensembles agree that some form of elevated sustained winds, possibly up to gale-force, will occur. Soundings show a cold airmass well below 0C being advected in with deep mixing, reinforcing this notion. Details of this event will continue to evolve. Ridging follows into the weekend.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 732 AM EDT Tue Oct 13 2026

Low ceilings and visibility will affect all sites through this afternoon with MVFR even unlikely until this evening. With precip ending later this morning, a slow improvement is expected with over 50% chances of MVFR at all sites by 03Z. Expect northerly winds generally in the 5 to 10 kt range.

MARINE

Issued at 310 AM EDT Tue Oct 13 2026

Lake Superior: Northeast winds continue to gust to around 25-30kts early this morning, and the odd gale-force gust is not out of the question into the pre-dawn hours over the western arm. However, winds continue to trend downwards into the morning and early afternoon, while also turning more northerly; winds become 10kts sustained with 20-25kt gusts after sunrise, then gusts to around 15- 20kts persist over the eastern half of the lake through the evening and overnight hours. Correspondingly, waves subside throughout the day today, decreasing to around 2 feet by the evening. Another shot of cold air working in will allow northwest winds to pick up to around 20-25kts over the eastern half of the lake, and to around 20kts to the west, late tonight into Wednesday morning. Gusts taper from west to east Wednesday afternoon and evening. Waves briefly increase to around 3-5ft over the eastern half of the lake for the afternoon and evening. Winds fall back again Thursday, but increase rapidly late week with a potential for gales Friday into Saturday.

Northern Green Bay and northwestern Lake Michigan: Northeast winds continue to gust to around 20-25kts early this morning, with wave heights up to 3-5ft in northern Lake Michigan and up to 1-3ft in the Bay. Winds lay down shortly after sunrise, then increase slightly in the afternoon while backing to the northwest, with gusts to 15-20 knots. Wind and waves go light early Wednesday as high pressure moves in, and calm on Thursday. Late week could see a period of elevated winds to 25-30 knots, and potentially gales, from Friday afternoon into the evening.

MQT WATCHES/WARNINGS/ADVISORIES

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