Area Forecast Discussion

KEY MESSAGES

- Areas of dense fog are expected through Sunday morning, especially along and near east-central Lake Superior.

- Dry and mostly sunny weather this weekend with above normal temperatures.

- Temperatures trend hotter into next week, with widespread 90s possible mid to late week.

- Another round of showers and storms likely on Monday. Diurnally- driven showers and storms will be possible the remainder of the week (15-30% chance each day).

DISCUSSION

Issued at 307 PM EDT Sat Jun 6 2026

Afternoon GOES water vapor imagery reveals largely clear skies across the Upper Midwest and Great Lakes region amidst ridging aloft and weak sfc high pressure skirting through northern Ontario. Closer to home, a sharp temperature gradient is present across Upper Michigan where lingering moisture and cool N to NW onshore flow is allowing stratus and fog to hug the adjacent Lake Superior nearshores while likely scattered cu are found elsewhere. Current obs (as of writing this discussion) peg the Munising lakeshore at a balmy 50F while just a short drive south Menominee holds at 80F. This has made for a tricky temperature forecast today. What may be tricker is how persistent fog will be tonight into Sunday morning. Give decreasing winds and lingering moisture from recent rain, thinking areas of dense fog will become more widespread. Latest 12z HREF suggests a 60-90% chance for vis <0.5 mi hanging on across much of the central and eastern UP (greatest prob along the Lake Superior Lakeshores) through the morning hours before mixing out around noon. Light E/NE flow may persist fog near the northern lakeshores and upslope areas of the central UP longer. Otherwise, Sunday is shaping up to be another pleasant June day albeit a tad warmer than today across the interior west with highs poking into the low to mid 80s, 70s elsewhere. Should fog and or stratus linger as it did today along the lakeshore, another tricky temperature forecast with a strong temperature gradient may be in play, as is common this time of year.

Precipitation chances return early this coming week as a shortwave is lifted from the southern Plains into the Great Lakes amidst increasing height falls across the western CONUS. Ample moisture return from the Gulf in the form of PWATs climbing into the 90-99th climatological percentile will pose a heavy rain risk, although given the lack of rain received in the last month, most would welcome an additional soaking rain event. In addition to the increased moisture, warm temperatures, possibly the warmest experienced so far this early Summer, are expected into the midweek. The latest NBM suggests a high chance (60-90%) of surface temps exceeding 90F across the interior west and central Wednesday/Thursday. However, these temperatures may be inflated by the ensembles bias correction, which was been warmer than observed recently. Non-bias corrected ensembles such as the LREF, comprised of other global ensembles, suggests a low <30% chance for sfc temps reaching 90F this far north. Trends will continued to be monitored over the coming days. In addition, cloud cover and precip development may hinder peak temperatures from reaching the 90s. Trends in severe weather potential will be monitored as well as a sharp shortwave lifting through the Plains and Upper Midwest will lead to thunderstorm development Wednesday afternoon and evening. At this time, SPC highlights and severe weather risk across MN and northwest WI, including the far western arm of Lake Superior.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 127 PM EDT Sat Jun 6 2026

While high pressure was over the area northerly flow and a relatively moist boundary layer was helping to maintain fog over Lake Superior, advecting inland as low stratus and impacting CMX and SAW early this afternoon. Expect CMX to clear out over the next hour as drier air works into the area. SAW will remain on the edge of the cloud shield over the next few hours but by later this afternoon conditions should improve to VFR.

Tonight the winds will go light under clear skies. This, combined with moist air in the low levels will result in widespread fog late tonight into the early morning hours at CMX and SAW. Light southerly flow may keep fog out of the IWD area and did not mention in the TAF at this time.

Fog will lift through the morning hours on Sunday with VFR conditions and light winds the remainder of the TAF period.

MARINE

Issued at 307 PM EDT Sat Jun 6 2026

Areas of marine fog have been persistent today across much of the central and eastern lake, however, satellite trends and area webcams reveals clearing taking place this afternoon. Still, stubborn fog and stratus are most persistent along the immediate lakeshores between Marquette and Whitefish Point. Opting to extend Marine Dense Fog Advisories through this evening for the west half of the lake where satellite reveals transient areas of fog/stratus. Should fog expand and persist there tonight, an extension may be warranted. Elsewhere, advisories for the central and east half of the lake have been extended through Sunday morning where confidence is greatest that fog will linger longest. Otherwise, winds are expected to remain below 25 kts through the forecast period. Active weather returns Monday/Tuesday with returning chances for showers and a few thunderstorms, which may create localized gusty winds. Looking further ahead, stronger thunderstorms may pose a hazard to mariners and recreationists alike on Wednesday. The latest SPC convective outlook highlights the western arm of Lake Superior for potential severe thunderstorms capable of producing strong winds and large hail. While the details are murky at this time, continue to monitor the forecast for ongoing trends and updates.

MQT WATCHES / WARNINGS / ADVISORIES

Upper Michigan... None. Lake Superior... Dense Fog Advisory until 8 AM EDT Sunday for LSZ247>251- 265>267.

Dense Fog Advisory until 8 PM EDT this evening for LSZ263-264.

Lake Michigan... Dense Fog Advisory from 8 PM this evening to 10 AM EDT Sunday for LMZ250.