textproduct: Marquette

KEY MESSAGES

- Dry weather persists through midweek with above normal temperatures.

- Humidity will fall into the 20-25% range over interior locations during the daytime hours through early next week along with warm temperatures, resulting in at least borderline elevated fire weather conditions.

- Next chances of showers and thunderstorms is in a window from early Thursday to late Friday, but uncertainty in the details is high. Additional chances for convection linger into the weekend.

DISCUSSION

Issued at 257 PM EDT Sun May 31 2026

Afternoon GOES-East imagery shows clear skies over the UP today with fair-weather cirrus remaining south of the state line and over far western Lake Superior. Aloft, the upper air pattern is characterized by a persistent omega block, with the center of the ridge extending from IL to Manitoba and the closed lows over New England and the Northern Rockies. At the surface, high pressure is centered over the Great Lakes, with light SE winds across much of the UP and northern WI. However, surface obs and radar imagery indicate lake breeze development off of both Superior and Lake Michigan. These look to penetrate rather far inland through the rest of the afternoon. Under sunny skies, temperatures have been able to rise into the mid and even upper 70s for most, and should climb further into the 80s in the interior-western and central UP. Behind the lake breezes, however, temperatures are falling back into the 60s to lower 70s. Dewpoints are falling into the 30s over the interior, and may even flirt with the upper 20s closer to the WI border. This is yielding RH currently near and even below 20% for much of the interior, but light winds will limit the threat for fire spread. Still, mind those burn restrictions.

Tonight, clear skies and light winds will help temperatures drop into the lower to mid 40s for most, though some of the guidance has values dropping a little further tonight, so it wouldn't be shocking if some spots fall below the 40 degree mark. Monday, high pressure currently centered over Hudson Bay slowly expands southward into the Great Lakes. As such, yet another day of summerlike temperatures and RHs falling to the 20s in the interior will occur. Winds will be more consistently out of the east to northeast and the deterministic NBM suggests wind gusts in the afternoon around 20 mph in the interior west, which could necessitate a fire weather SPS.

By Tuesday, the ensemble mean 500mb chart suggests that the weather pattern will finally begin shifting as the eastern closed low shifts off the Newfoundland and Labrador coast while the western low shifts north into Manitoba and Saskatchewan. The ridge remains amplified over the Great Lakes through Tuesday, but begins to break down Wednesday as the western low tracks eastward. While there is spread in the details, the global deterministic suite agrees that the western low becomes a trough that tracks over Lake Superior and northern Ontario throughout the PM hours of Thursday to Friday PM. This will give us our next chances of precipitation, though global models are notoriously poor at determining the breakup of a blocky pattern, so confidence is only high enough to provide a broad window of unsettled weather. Still, will note a surge of moist Gulf air into the region on the backside of the exiting ridge with PWATs climbing above-normal Thursday onwards. LREF mean SBCAPE values of around 250 J/kg in the afternoons for Thursday and beyond will give at least some potential for thunderstorms mainly in the interior west, though it is far too soon to tell if there is any severe potential. The chances for a wetting rain will be a welcome relief for those concerned with fire weather as chances of 0.1"+ of precip by the end of Thursday ranges from around 35% in the east to around 70% in the west with widespread 50-70% chances of over a quarter inch of rain by late Saturday. Otherwise, NBM favors Wednesday for the warmest temperatures of the week, when 850mb temperatures nearing as high as 12-15C support highs well into the 80s in the interior-UP. Thereafter, temperatures return to the more-familiar 70s and 80s for the afternoon hours with lows in the 50s

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 111 PM EDT Sun May 31 2026

VFR conditions will prevail through the TAF period with mainly clear skies. A lake breeze will push through SAW near the start of the TAF period, bringing northeasterly winds for the afternoon and early evening. Otherwise mainly light and variable winds can be expected.

MARINE

Issued at 257 PM EDT Sun May 31 2026

Blocked weather pattern aloft leaves high pressure from the Upper Great Lakes to Hudson Bay through the first half of the work week, leading to an extended period of time where virtually all of the lake will be in mild conditions with gusts sub-20 kt. The exception will be on Monday afternoon and evening, where northeasterly flow accelerates down the western arm of the lake to 20-25 kt, briefly driving 3-4 ft waves. As the pattern breaks up in the midweek and progresses, the next chance for gusty conditions and some thunderstorm potential is late in the week, though model spread by that point decreases confidence in the details. Chances of wind gusts exceeding 25 kt is around 10-30% for any given period between Thursday night and Saturday.

MQT WATCHES/WARNINGS/ADVISORIES

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