textproduct: Marquette

KEY MESSAGES

- A few showers and non-severe thunderstorms are possible in the Keweenaw and northern tier of the UP this afternoon and evening, otherwise dry weather is expected into the rest of the week.

- Seasonably warm temperatures in the low to mid 80s dominate this week.

- Patchy dense fog is possible tonight, especially in the Keweenaw and closer to the Lake Superior shoreline.

DISCUSSION

Issued at 233 PM EDT Mon Jul 27 2026

Afternoon GOES satellite imagery reveals mostly clear skies overhead Upper Michigan with increased subsidence and dry air advection behind this morning's round of thunderstorms. A few remaining scattered showers are noted on the Thunder Bay, Canada radar approaching Isle Royale, but overall thinking strong thunderstorm potential is very limited as these showers/storms cross the island and work towards the Keweenaw. Thus, the remainder of the evening should remain largely precip free across the UP. Also noted on satellite imagery is the presence of transient marine fog across much of Lake Superior. With an uptick in northerly winds expected, marine fog may hug the shorelines and Keweenaw Peninsula, though confidence is low on if it will penetrate inland anywhere overnight. Partly cloudy skies should allow low temperatures to fall into the 50s to low 60s tonight, warmest near the lakeshores.

Quieter weather can be expected headed into the rest of the week as the seemingly endless Plains ridge churns and geopotential heights build into the Upper Midwest / Great Lakes. Seasonably warm temps in the mid to low 80s will be the rule through at least Friday. A flattening of the ridge and more zonal flow aloft later this week (Thursday-Friday timeframe) brings returning PoPs to the forecast, but for now enjoy some classic summer days ahead.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 150 PM EDT Mon Jul 27 2026

Regional radar shows this morning's showers and storms departing well to the south and east over WI and Lower MI, leaving mostly VFR conditions in place across Upper MI with the exception of some lingering stratus and IFR cigs at KCMX. Expect VFR to generally persist into this evening with north to northwest winds around 10 kt behind the departing front. Guidance continues to hint at fog for all terminals tonight as surface high pressure builds in from the north atop a moist boundary layer given today's rainfall. Expect a downward trend towards IFR/LIFR after 06z tonight. Conditions then improve back towards MVFR after 12z Tue as northerly winds pick back up to around 10 kt Tue morning.

MARINE

Issued at 233 PM EDT Mon Jul 27 2026

Breezy northerlies between 15-20 kts will be common tonight before settling below 15 kts lake wide tomorrow. A few gusts 15-20 kts may linger closer to Whitefish Bay. Otherwise, transient marine fog will be the primary hazard for the near term. Marine Dense Fog advisories have been issued for all of our Lake Superior zones through 12z tomorrow, with the possibility of extending some areas as fog persists.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... Dense Fog Advisory until 8 AM EDT /7 AM CDT/ Tuesday for LSZ162-240>251-263>267.

Lake Michigan... None.