textproduct: Marquette

KEY MESSAGES

- Dry weather persists into the early weekend with high pressure over the area. High temperatures start climbing above normal today toward near 70 this weekend.

- A few rain showers may graze the western UP late Saturday into early Sunday, but more widespread chances for rainfall hold off until midweek next week.

DISCUSSION

Issued at 208 PM EDT Wed Sep 23 2026

Visible satellite shows hardly a cloud in the sky over the UP this afternoon, with high pressure centered over southern Quebec sending ridging into the Great Lakes and water vapor revealing dry midlevel air over the region. Under sunny skies, temperatures are climbing a couple degrees higher than yesterday, already in the lower to mid 60s across much of the UP. Expect temperatures to peak in the mid to upper 60s for most this afternoon. Light winds and clear skies will allow temperatures to radiate out nicely again tonight, but we should still come in a couple degrees warmer than in previous nights as a shift over to southerly flow brings in a comparatively warmer airmass. Lows range from the mid/upper 30s inland to the 40s near the lakeshores. This should limit the extent of any frost to just the coldest spots. Otherwise, model soundings show enough moisture at the lower levels to support at least some patchy fog overnight, but this should not be particularly impactful.

Another quiet day is expected Thursday with ridging over the area, but clouds increase during the afternoon and evening as a midlevel shortwave moves out of the Plains and heads towards the Great Lakes. This could graze western Lake Superior and even the far western UP with some showers Thursday evening through the first half of the night, but there is a very dry airmass to contend with. Simulated reflectivity per the CAMs seems overly enthusiastic regarding the extent on any showers late Thursday, so will continue to lean towards the NBM solution which keeps the UP dry. Similar to today, temperatures should rebound into the mid 60s for most Thursday afternoon, but some spots may crack the 70 degree mark during the afternoon. Dewpoints look to mix out nicely once again, dropping back into the mid/upper 40s by the afternoon. This would yield minimum RH as low as the low/mid 40%s, lowest across the eastern UP where less cloud cover would support better mixing. Southerly winds remain tame, with gusts below 15mph, limiting the threat for fire spread.

Skies clear out Friday as ridging recovers in the wake of the exiting shortwave. High temperatures reach 5-10 degrees above normal, peaking in the upper 60s to lower 70s. Split flow continues through Saturday as anomalously strong Canadian high pressure is mostly maintained, and the conjoining mid-level low deepens off the mid-Atlantic coastline. Saturday evening, a second shot of moisture rides the windward edge of a ridge centered over the Great Lakes north toward Saskatchewan. Chances for showers scrape the western UP late Saturday into Sunday morning as another weak shortwave ripples through. Sometime Monday, high pressure at last appears to break down over eastern Canada as a trough approaches from the North Pacific. By midweek, ensembles and deterministic guidance bring this through the Great Lakes either as an open trough or a deep midlevel low, with some phasing it with another more southerly feature. So, significant differences in the particulars as we enter the chaos region of the guidance, but more widespread chances for rain finally return midweek next week.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 812 PM EDT Wed Sep 23 2026

Primarily VFR conditions are expected during the 0Z TAF period at the TAF sites as high pressure continues to extend overhead. The exception to this is at SAW where BR/FG probabilities have increased enough to include MVFR VIS mention early Thursday morning (40-60% chance for <=5SM). IFR VIS probabilities range between 20-40%, LIFR or lower VIS probabilities are only between 10-25%. Otherwise light southerly winds settle to around 5 kts tonight, increasing to around 8 kts on Thursday with gusts between 10-15 kts; winds shift east at CMX Thursday afternoon. Broken high clouds increase gradually from the west on Thursday.

MARINE

Issued at 208 PM EDT Wed Sep 23 2026

For Lake Superior: Easterly winds gusts pick up to around 20kts by the late afternoon, with some stronger gusts to 25kts in the nearshore areas of Keweenaw Bay and towards Duluth. Wave heights increase to 2-3 ft by late evening. These elevated winds turn southerly through tonight prior to becoming isolated to the east- central portions of the lake into Thursday afternoon, at which point wave heights subside to 1-2 feet. Winds fall back below 10kts across the entire lake Friday while waves decrease to 1 foot or less. Southerly wind gusts up to 20kts develop again Saturday ahead of a shortwave, then winds fall back into Sunday, diminishing to 5-10 knots on Monday.

For the Bay of Green Bay and Northern Lake Michigan: Easterly wind gusts to 15-20 knots will be common the rest of the afternoon and evening hours, slowly falling back after midnight. During this time, wave heights pick up to 3-4 feet in Lake Michigan and 2-3 feet in the Bay of Green Bay. Winds shift over to the E/SE Thursday, falling below 15 knots, and then go very light from the south on Friday. Wave heights subside to below 1 foot by Friday morning. Winds remain below 10 knots through Sunday.

MQT WATCHES/WARNINGS/ADVISORIES

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