textproduct: Marquette

KEY MESSAGES

- Warm and humid conditions persist this afternoon, though the heat index will remain below heat advisory criteria. Be sure to stay hydrated and have a way to cool off.

- Spotty showers and thunderstorms develop along the lake boundaries this afternoon, winding down this evening. Gusty winds are possible in storms.

- Temperatures will be closer to average for the holiday weekend along with notably drier air as dew points fall back into the 50s to low 60s.

DISCUSSION

Issued at 233 PM EDT Fri Jul 3 2026

Afternoon water vapor imagery and RAP analysis reveal upper level high pressure centered over the Blue Ridge mountains, with zonal flow over the Midwest and Great Lakes. Embedded shortwaves throughout the region are remaining outside of the UP, but associated high cloud cover is continuing to stream into the area at times. Closer to home, lake breeze development has become apparent on radar and visible satellite, with plenty of cumulus popping away from the lakeshores. Some storms are already developing along the Superior lake breeze over Luce county, and it would not be surprising to see agitated cu and eventually showers/storms develop westward as well. Scattered showers and storms become more likely over the central and southern UP as the Superior lake breeze continues to move inland and potentially interacts with the Lake Michigan boundary. SBCAPE is already analyzed to be in excess of 2000j/kg across the UP, with several hundred j/kg of DCAPE. Still, shear is quite lacking. So, organized severe convection is not expected, but a stronger gust is not out of the question as storms collapse again. Will also note that SPC has removed us from the Marginal risk.

Otherwise, we are enjoying a pleasantly sunny summer day, with temperatures ranging in the lower to mid 80s for most away from the lakeshores. Temperatures are expected to peak slightly higher in the mid/upper 80s inland, highest over Menominee county, while the lakeshores only peak in the 70s (or even lower nearest to Superior).

The rest of the holiday weekend, temperatures moderate some as high pressure centered over Hudson Bay extends ridging southward and allows a cooler airmass to sink southward. Still, temperatures won't exactly turn cold, with highs ranging in the 70s to lower 80s and lows mainly in the 50s. Meanwhile, yet another shortwave will be moving out of the Plains and towards the Great Lakes Saturday. Much of the deterministic and ensemble guidance favors a weaker wave that stays more to our south, somewhere over WI, while the GFS is both stronger and more north with this wave. NBM in turn keeps the better PoPs south of our borders, with just chance PoPs over the UP Saturday evening into Sunday. If this batch can move over the UP, we aren't exactly looking at a washout; a tenth to quarter-inch would be the more likely scenario, but higher amounts would be possible Temperatures trend warmer again into next week as ridging recovers, and though drier weather is favored, diurnal instability presents almost daily chances for some convection. There are hints for another trough and cold front to sweep through sometime midweek, which brings better chances for convection in the Wed-Thurs timeframe.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 148 PM EDT Fri Jul 3 2026

Lingering MVFR cigs around FL025 in the vicinity of KIWD and KCMX early this afternoon should dissipate through about 20z. Expect scattered showers and thunderstorms to develop later this afternoon along well defined lake breeze boundary already noted on radar and satellite imagery, resulting in PROB30s for -TSRA at KIWD and KSAW into this evening. This activity will remain well south of KCMX. Storms will dissipate by around 00z, with VFR conditions expected thereafter through the end of the period as drier air begins to filter into the region.

MARINE

Issued at 233 PM EDT Fri Jul 3 2026

Afternoon satellite reveals at least some lingering patchy fog over the open waters, and available webcams show this is dense at times. Otherwise, dense fog is becoming more widespread in the nearshores off the western UP, so fog headlines will go up there. Otherwise, quiet weather persists today with variable winds coming in below 15kts. Weak winds to start off increase out of the northeast Saturday afternoon and evening as another trough moves through the Great Lakes, with gusts up to 20-25kts over the western arm of the lake. This may also bring some showers and storms over the lake Saturday into Sunday, though confidence is low. Northeast winds gradually decrease Sunday, and remain light into next week. Dry weather becomes favored after Sunday, but daytime instability nevertheless leads to at least some potential for afternoon showers and storms.

MQT WATCHES/WARNINGS/ADVISORIES

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