textproduct: Marquette

KEY MESSAGES

- Isolated showers linger today, mainly over the eastern two thirds of Upper Michigan.

- Temperatures fall back into the mid 60s to upper 70s for the weekend, coolest near Lake Superior. Lower dewpoints will result in a more comfortable airmass on Sunday and Monday.

- The chance for showers and thunderstorms returns on Tuesday as a cold front approaches the area.

DISCUSSION

Issued at 307 AM EDT Sat Aug 1 2026

Early morning GOES WV imagery shows the mid level trough now over the Upper Mississippi River Valley with RAP analysis plotting the associated 1004 mb low now over northern IL. A cold front is pressing south over the CWA early this morning while the abundant moisture from yesterday begins to exit. With instability falling and deep moisture dissipating, shower activity is tapering down and thunder has ceased. That said, isolated to scattered showers closer to the low over the east half of the UP and northerly upslope drizzle are both possible today as a secondary cold front progresses south overhead. Low level moisture will remain high, possibly resulting in patchy fog, mainly over the east half this morning. Cooler temps today in the 60s and 70s, coldest near eastern Lake Superior. As the UP dries out for tonight under weak high pressure ridging, colder temps are expected in the mid 40s to upper 50s, coldest interior west.

Notably drier air can be expected for Sunday into Monday with dewpoints in the 50s, resulting in more comfortable conditions. Temperatures will be in the mid 60s to 70s on Sunday and upper 70s to low 80s on Monday (close to seasonal averages).

On Tuesday humidity will begin increasing ahead of an approaching cold front. Showers and thunderstorms may accompany the front on Tuesday but the risk for organized convection remains uncertain at this point in time, with global models showing lower instability and shear. It will fall back into the 70s for Wednesday behind the front with a rebound again on Thursday along with a slight chance for thunderstorms.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 747 AM EDT Sat Aug 1 2026

The 12Z TAF period will have BR/FG as well as low cig impacts to some degree at all sites, but winds and precip will not be a major concern. MIFG at IWD should quickly clear out, leaving VFR through most of the period until additional radiational BR/FG develops early Sunday morning. CMX is currently socked in at minimums from marine FG aided by northerly upslope flow. Model guidance is not handling this well, but generally points to improvement to VFR by or shortly after 15Z; amendments may be needed as BKN mid level clouds clear out giving a better view at the marine low cigs/FG. SAW begins in VFR, but sees BKN MVFR cigs return by late morning as the marine cloud deck moves inland. Periods of IFR/LIFR are expected this afternoon and early evening. Similar to CMX, confidence in timing is low, so opted to use a TEMPO group for now. SAW improves to VFR by tonight as FG clears and low cigs SCT out, but additional BR/FG development tonight can't be ruled out. Otherwise north to northeast winds increase to around 10 kts at all sites by this afternoon.

MARINE

Issued at 747 AM EDT Sat Aug 1 2026

The lake remains under a weak pressure gradient through the forecast, resulting in mainly light winds at or below 20 kts. Areas of dense fog will impact central and eastern Lake Superior this morning, pressing south and clearing from the west half and the far eastern corner by this afternoon. Fog may linger into the late afternoon over the south-central waters. Hoisted Dense Fog Advisories to reflect impacts today. Showers and thunderstorm are expected again on Tuesday but there remains uncertainty as to the the coverage and strength of the storms.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... Dense Fog Advisory until 11 AM EDT this morning for LSZ242>244- 264.

Dense Fog Advisory until noon EDT today for LSZ245.

Dense Fog Advisory until 5 PM EDT this afternoon for LSZ248>250.

Dense Fog Advisory until 2 PM EDT this afternoon for LSZ251- 267.

Dense Fog Advisory until 5 PM EDT this afternoon for LSZ265- 266.

Lake Michigan... None.