textproduct: Marquette

KEY MESSAGES

- Temperatures will remain very warm the rest of the week but likely below heat advisory criteria. Be sure to stay hydrated and have a way to cool off.

- There is an enhanced risk (30% chance) for severe thunderstorms across the far southern UP and a slight risk (15% chance) for the remainder of the UP, mainly this afternoon and evening. The main threat will be damaging winds though a few storms with large hail cannot be ruled out.

- There is a marginal risk (<15% chance) for thunderstorms again on Thursday, some of which could be strong to severe with damaging winds and large hail.

- Additional thunderstorms are possible through the rest of the week, some of which could be strong to severe through Friday.

DISCUSSION

Issued at 314 PM EDT Wed Jul 1 2026

Early afternoon satellite imagery and regional RAP analysis reveals a broad upper level ridge parked atop the southern Appalachians while another ridge riding shortwave graces the northern Great Lakes. This has resulted in a few rounds of showers/storms in the vicinity of the UP, largely missing us as a whole thus far save for areas near the WI stateline. Convective debris and mid level cloud cover has kept the rest of the area capped, though satellite trends show clearing and the rebuilding of surface based instability south- central and back into northern Wisconsin. Scattered thunderstorms may redevelop along remnant modified outflow boundaries this afternoon and early evening, though spatial extent and timing is uncertain. CAM guidance, as per usual, continues to struggle as well, though there may be a signal for greater convergence and scattered storm coverage in the west half through 00z tonight. Greater coverage of storms is more likely to occur later tonight into the overnight hours across portions of the far south-central where ascent ramps up ahead of the nocturnal LLJ. SPC continues to highlight an Enhanced Risk (level 3/5) clipping Menominee county, however, consensus among CAMs suggests the threat has shifted further south largely out of the UP. Certainly cant rule out some strong to severe thunderstorms capable of producing damaging winds and small hail, albeit confidence is waning. Otherwise, temps have managed to rise into the low to mid 80s this afternoon with a few spots pushing the upper 80s. With dewpoints still anomalously high in the upper 60s and low 70s, peak afternoon heat indices will poke into the 90s. Continue to practice heat safety measures! Temps fall back into the upper 60s tonight. Diurnal instability underneath a weak shortwave may support additional scattered thunderstorms tomorrow afternoon.

The pattern remains active with chances for showers and thunderstorms just about every day through the holiday weekend. The upper level jet will weaken this weekend and the risk for severe thunderstorms will go down. It will remain very warm and muggy through Thursday with the heat index in the upper 80s to mid 90s. Dew points fall back into the low 60s with somewhat cooler highs in the low to mid 80s late week into the weekend, with heat indices staying in the 80s.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 202 PM EDT Wed Jul 1 2026

Visible satellite and radar imagery as of 18z Wed show abundant high level clouds spreading across Upper Michigan as ongoing convection remains mostly to the south across northern WI and northern Lower MI, with one stronger cell clipping Menominee County. Thunderstorms remain the primary concern through the period as latest guidance continues to struggle with potential timing and coverage of storms across the UP through this evening. Will maintain PROB30s at KIWD and KSAW through 03-06z window this evening. Thunderstorm probs remain low enough (~20%) at KCMX to just carry -SHRA for now. VFR expected through the end of the period at all sites with southwest to westerly surface winds around 10 kt, except more gusty and erratic winds possible near thunderstorms.

MARINE

Issued at 314 PM EDT Wed Jul 1 2026

The main marine hazards over the next few days remain to be dense fog and thunderstorms, some strong to severe with gusty winds and hail tonight. A very humid airmass will continue to spread across the lake resulting in areas of dense fog, especially anywhere rainfall is occuring or occurs. Additional thunderstorms are possible through the rest of the week but the potential for severe thunderstorms over Lake Superior will decrease on Thursday. Weak gradient flow will result in light winds, below 15kts through the weekend, with the exception of stronger winds in the vicinity of thunderstorms.

MQT WATCHES/WARNINGS/ADVISORIES

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