textproduct: Marquette

KEY MESSAGES

- Dry weather persists through Wednesday with above normal temperatures.

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

DISCUSSION

Issued at 356 AM EDT Tue Jun 2 2026

Little change in the forecast this morning as a well defined omega block continues to dominate the upper level pattern. RAP analysis depicts the ridge axis extending from Hudson Bay through the Upper MS River Valley to the Central Plains, with a pair of lows centered over Montana and Newfoundland respectively. Clear skies and light winds over the U.P. have allowed temperatures to drop towards the lower end of guidance overnight, with widespread lows in the low 40s and even a few 30s away from the lakes. Surface high pressure will migrate directly overhead from Hudson Bay and northern Ontario today while 850 mb temps increase slightly to 10-12 C. This will push highs a few degrees warmer than yesterday, with many locations reaching the upper 70s to mid 80s. Relative humidity values will bottom out in the low 20s in most locations away from the immediate lakeshores this afternoon, but light winds will serve to limit any fire weather concerns. Expect temps may drop a bit lower than guidance again tonight given the persistent clear and calm pattern remaining conducive to optimal radiational cooling processes.

The omega block will begin to gradually break down today, with ensemble guidance indicating that the main ridge will de-amplify with higher thicknesses collapsing progressively southeastward over the region until Wednesday night. This means high pressure will continue to dominate at the surface through this decay process, with dry, backing gradient flow and light winds at the surface. Thus, expect widespread very dry afternoon RH's in the low 20's through Wednesday afternoon prior to the next pattern shift. High temperatures increase through Wednesday, reaching the high 80s in the interior west and low 80s elsewhere on Wednesday afternoon. Fire weather concerns will remain limited, however, due to lack of wind. Take care to hydrate proactively, and check burn bans.

Ensemble guidance indicates that Wednesday night into Thursday will bring about the final collapse of the decaying ridge from the omega block as the Montana low propagates eastward, reaching Ontario by midday Thursday. At this point, however, deterministic models suggest the low will dissipate as ridging builds in quickly behind it into Friday. Although the passage of this low coincides with a plume of anomalously high PWAT reaching the UP from the Gulf as shown by the LREF and ECWMF EFI, guidance suggests minimal synoptic forcings at this time. From a buoyancy standpoint, however, the LREF shows above up to 70% probability of 250 J/kg of MUCAPE entering the western UP early Thursday morning, and 10-20% probability of 1000 J/kg of MUCAPE in the CWA Thursday evening. Between Thursday and Friday, LREF shows 30-40% chance of 6-hour precipitation greater than 0.1", with higher accumulations in the western UP. So for Thursday and Friday, chances exist of a wetting rainfall accumulations and a thunderstorm or two, but the threat of severe weather is minimal.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1252 AM EDT Tue Jun 2 2026

High pressure becomes centered over the Great Lakes this morning maintaining VFR flight conditions through the duration of the 6Z TAF period. With no precip or fog expected and few high clouds passing overhead, the focus is on light winds. Winds hold 5 kts or less through this morning before lake breezes begin impacting the sites. This will increase easterly winds at CMX/SAW to around 10 kts. It remains unclear if this boundary will overcome the southerly flow at IWD. If the boundary does press past IWD, confidence in that timing is low. Opted to include variable winds at the most likely onset of this boundary passage for now.

MARINE

Issued at 356 AM EDT Tue Jun 2 2026

High pressure over the Great Lakes will keep winds below 20 kt through Wednesday. The high shifts east Wednesday night into Thursday with southerly wind gusts around 20 kt. There will be a slight chance of thunderstorms ahead of a weakening disturbance Wednesday night into Thursday night.

MQT WATCHES/WARNINGS/ADVISORIES

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