textproduct: Marquette

KEY MESSAGES

- A few scattered showers and thunderstorms are possible near the state line and south-central UP this afternoon and evening.

- Scattered showers and isolated thunderstorms will be possible at times into early next week, but severe weather and heavy rainfall are not expected, and it's not likely that any day becomes a washout.

- Temperatures remain below normal this into early next week.

DISCUSSION

Issued at 229 PM EDT Thu Jun 18 2026

Afternoon GOES satellite imagery reveals the shortwave responsible for this morning's round of rain has departed east of Lake Superior, leaving partly cloudy skies in its wake. A low amplitude shortwave is working in tandem with building diurnal instability to kick off scattered showers and maybe a few rumbles of thunder near the state line, as noted by a recent uptick in agitated cu and light radar returns down there. Better forcing near upstream Thunder Bay is throwing scattered showers and storms into Isle Royale, thus have added some low end PoPs for the Natl Park. Some CAM guidance suggests this shower activity crossing the NW lake into the Keweenaw, but confidence is low on this scenario considering ample overlake stability. Will need to keep an eye on this area and append the PoP forecast for the Keweenaw should scattered convection survive the trip across the lake. Otherwise, looking like a wonderful June day with current temps poking into the upper 50s and 60s amidst breezy NW winds. Any diurnally driven precipitation will taper off tonight before temps fall into the 40s to near 50, warmest along the lakeshores. Another weak shortwave descends into the northern Great Lakes late Friday, potentially driving another round of scattered showers through the UP during the evening and overnight hours into Saturday morning. CAM ensembles hint at lake breeze driven convection Saturday afternoon, largely across the "Golden Triangle" of the central UP. Sunday looks to remain dry in our neck of the woods.

The seemingly endless period of troughing begins to break down early next week into the midweek period, allowing more zonal flow aloft and the passage of additional shortwaves from the northern Rockies to emanate into the region. Chances for more widespread meaningful rainfall (25-50% of >0.25") returns in the Tuesday-Wednesday timeframe.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 100 PM EDT Thu Jun 18 2026

The last of the showers have left the area as VFR conditions dominate the TAF period. While WNW winds lower tonight, they look to pick up once again Friday morning.

MARINE

Issued at 229 PM EDT Thu Jun 18 2026

Breezy NW winds are present this afternoon gusting between 25-30 kts across the central lake, mainly between Marquette and Whitefish Point. Winds fall between 20-25 kts or less tonight before falling below 20 kts lakewide Friday PM. A period of calmer winds <15 kts is expected through the rest of the weekend and into the coming week.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Beach Hazards Statement until 10 PM EDT this evening for MIZ006.

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