textproduct: Marquette

KEY MESSAGES

- Dry weather persists through Wednesday with above normal temperatures.

- Scattered showers and thunderstorms return early Thursday, with another round Friday afternoon and evening. Uncertainty remains regarding precise timing and rainfall amounts in storms. Additional chances for convection linger into the weekend.

DISCUSSION

Issued at 300 PM EDT Tue Jun 2 2026

Afternoon water vapor imagery and RAP analysis reveal well-defined closed lows spinning over northern Montana and Nova Scotia. This yields steep ridging over the Great Lakes region, with surface high pressure currently centered right over the UP. Apart from some cirrus streaming into the far western UP, with a quiet and mild day as temperatures so far in the mid/upper 70s for most of the interior climb further into the lower 80s. Lake breeze development apparent on radar imagery and surface obs is helping to keep temperatures cooler nearer to the lakeshores, where highs may only reach the 60s to lower 70s. Under sunny skies, dewpoints are mixing out quite nicely into the mid 30s, yielding RH so far at around 20-25%; lower values in the teens are not out of the question. Light winds continue to limit the threat of wildfire spread, but nevertheless, mind those burn bans.

Tonight into Wednesday, our omega block pattern continues to break down as the aforementioned closed lows begin to work eastward and the ridge over our region de-amplifies. This means high pressure will continue to dominate at the surface through this decay process, with dry, backing gradient flow and generally light winds at the surface. That said, as the gradient tightens slowly over us Wednesday, some 15-20mph gusts are not out of the question into the afternoon particularly over and onshore of Lake Michigan. 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. This, combined with comparatively more breezy conditions (as opposed to today) may lead to elevated fire weather conditions. 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 sometime Thursday afternoon to early evening. At this point, however, deterministic and ensemble guidance suggest the low will dissipate as ridging builds in quickly behind it over the Canadian Prairie into Friday. At that point, flow over the Great Lakes will be more zonal, but sensitive to additional, poorly-timed shortwave action emanating out from the Northern Plains during the daytime hours Friday. A more vigorous shortwave digs into the Great Lakes Friday evening into early Saturday. What does this mean for our precip chances as we finish out the work week? Although the passage of the initial low Thursday coincides with a plume of anomalously high PWAT reaching the UP from the Gulf, guidance suggests minimal synoptic forcings at this time. From a buoyancy standpoint, however, the LREF up to 70% probability of 250 J/kg of MUCAPE over the western UP early Thursday morning, and 20-40% probability of 1000 J/kg of MUCAPE in the CWA Thursday evening. By Friday evening, several hundred j/kg of MUCAPE is analyzed over the region. That said, shear both days is limited, but this does point to a chance for thunderstorms, some marginally severe, both days. Thursday, LREF shows 30-40% chance of 6-hour precipitation greater than 0.1", with higher accumulations in the western UP. Friday, probabilities jump up to 30-60%. Higher totals in excess of a quarter-inch would be possible where thunderstorms develop. So for Thursday and Friday, chances exist of a wetting rainfall accumulations and a thunderstorm or two, but coverage remains in question, and the threat of severe weather is minimal.

Chances for convection linger into Saturday before ridging builds in again for Sunday and early the following week. After temperatures turn more seasonable Thursday through Saturday, they trend upwards again thereafter with some of the interior-UP taking a run at the 90 degree mark.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 116 PM EDT Tue Jun 2 2026

High pressure ridging overhead will keep VFR conditions going as some SCT high-level clouds move through the U.P. tonight into Wednesday. Winds will remain light today (mainly lake breeze driven) before becoming SW'rly late tonight into Wednesday.

MARINE

Issued at 300 PM 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, and again Friday. Otherwise, expect winds to fall below 20kt for Friday onwards while ridging returns to the region into early next week.

MQT WATCHES/WARNINGS/ADVISORIES

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