textproduct: Marquette

KEY MESSAGES

- Patchy, locally dense fog over the central and eastern UP this morning. More fog possible over the west tonight.

- High temperatures remain slightly slightly above average in the upper 60s to low 70s through the first half of the coming week.

- A few rain showers may graze the western UP this morning, but chances for more widespread rainfall hold off until Tuesday into Wednesday.

DISCUSSION

Issued at 222 AM EDT Sun Sep 27 2026

An omega-like blocking pattern remains in place this morning, with the axis of the upper level ridge centered directly over the UP between deep troughing centered over western Canada and the Mid Atlantic. Water vapor imagery reveals a weak disturbance riding up the western periphery of the ridge, bringing extensive cloud cover over the western half of Lake Superior and the western third of the UP. A few radar echos are noted over western Superior into the MN Arrowhead. Farther east where skies remain clearer, patchy fog is developing across parts of the central and eastern UP, becoming locally dense in a few spots. A few rain showers will clip the far western UP later this morning, but guidance continues to keep any measurable precipitation minimal and confined to Gogebic and Ontonagon Counties, with a around a 25% chance for as much of a tenth of an inch around Ironwood today. Several CAMs seem rather bullish on these showers making farther east into the central UP this afternoon, but there will be quite a bit of mid level dry air to contend with and, as such, have opted to keep the forecast completely dry for all but the far western UP today. Thus expect another day of highs in the upper 60s to low 70s under partly cloudy skies. Minimum RH values could dip into the low 40s or even as low as the mid 30s across parts of the central and eastern UP this afternoon, but light winds will keep fire weather concerns limited as they have been in recent days.

Expect more fog development tonight as skies partially clear out this evening, aided in the west by any precipitation that falls today. Monday will then be another seasonably warm and dry day as high pressure lingers over the Great Lakes, with highs in the low to perhaps mid 70s in a few spots near the WI border. High pressure breaks down on Tuesday and paves the way for a more progressive zonal flow pattern with embedded shortwaves traversing the region through the rest of the week. The first of these will impact the UP late Tuesday into Wednesday as low pressure ejects out of the Plains while a shortwave tracks across northern Ontario, bringing a period of more widespread rain to the UP. Latest NBM maintains around a 40% chance for a wetting rain of a quarter inch across most of the area through Wednesday morning, closer to 60% across the southcentral UP. Another shortwave crossing northern Ontario on Thursday will bring potential for breezy conditions as well as additional rain chances. Temperatures generally look to remain slightly above average in the upper 60s to low 70s through the first half of the week before eventually settling back into the low to mid 60s later in the week.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 733 AM EDT Sun Sep 27 2026

A weak shortwave is kicking off a few scattered light rain showers near IWD this morning but is not expected to push any further east. Patchy dense LIFR fog may be observed early this morning at SAW before dissipating with sunrise. Additional fog development is expected around the end of the TAF period at IWD/CMX. Otherwise light southerly winds persist around 5 kts until this afternoon when the shortwave shifts winds westerly. However, a lake breeze may press northeast winds into SAW instead before calm conditions return to all sites after sunset.

MARINE

Issued at 222 AM EDT Sun Sep 27 2026

Winds turn southerly today and remain below 20 kt under high pressure until Tuesday, when an approaching disturbance will drive wind gusts out of the south to increase to near 25 kt, highest near Stannard Rock. Winds eventually turn more westerly or northwesterly as the pattern changes mid to late week, with cold air advection driving gustier winds and increased gale chances (40-50% over the eastern half of Lake Superior) by Thursday. Waves will be highest for the nearshores of Lake Michigan, where the long-duration and long-fetch southerlies increase the waves to near 3 ft.

MQT WATCHES/WARNINGS/ADVISORIES

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