textproduct: Marquette

KEY MESSAGES

- A couple of isolated showers and thunderstorms are possible in the interior central/west U.P. this afternoon.

- A warming trend continues today through this weekend, bringing unseasonably warm temperatures and humid conditions into next week. This is leading to a potential for heat-related impacts to vulnerable populations.

DISCUSSION

Issued at 200 AM EDT Fri Jun 26 2026

Expect fairly calm and quiet weather today and through Saturday as high pressure ridging settles over the Upper Great Lakes the next couple of days. Thus, save for some fog being seen over the eastern U.P. early this morning, expect mostly clear skies to continue across the area this morning, before an upper-level cloud deck rolls through after sunrise. While mostly dry conditions are expected today, there may be enough instability that develops over the inland areas to create some isolated showers and thunderstorms over the interior west and central this afternoon. However, once the evening hours come, expect the U.P. to become quiet once again as the skies clear out.

Today through this weekend, expect the warming trend to continue, with highs in the 70s today giving way to highs in the 80s and 90s early next week. This warming trend is due to a pattern shift aloft via a PacNW low moving through the Rockies this weekend before lifting into the Canadian Prairies early next week. This will set us up with Gulf air, bringing anomalously warm temperatures and humid conditions overhead. Thus, with the NBM highlighting high temperatures approaching 100 in some spots in the west and central Monday and Tuesday, some heat related products (like a Heat Advisory) may need to be issued in the future given the stress the hot and humid weather may cause. In addition, with shortwaves expected to roll into the region from Colorado and the Southern Plains next week, we could see several rounds of showers and thunderstorms across the area; with the European EFI highlighting CAPE and shear (mostly CAPE though) close to the max of modeled climatology, and with some areas of the U.P. approaching a Shift-to- Tails close to 1, there is certainly a non-zero chance for some severe weather early next week (somewhat big 'boom' potential). However, given that this is not our typical flow regime for severe weather, there are significant doubts on if this will actually materialize or if this will be yet another 'bust' prediction again for this summer (severe weather threats are over-estimated from more southwesterly flow regimes so far this summer). Temperatures may taper a few degrees as we head towards the later half of next week. That being said, expect the very warm conditions to continue to the end of the forecast period and beyond as southerly flow from the Gulf continues.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 117 AM EDT Fri Jun 26 2026

VFR conditions prevail at all sites tonight with winds below 10 kt and clear skies. Once again, uncertainty around fog overnight tonight will be the main forecast question. Models differ on how dense the fog will be, with some hi res solutions suggesting 30-50% chances of at least MVFR fog at all sites, while other climatology- calibrated guidance suggests 20% or less chances of fog formation. This TAF issuance will reflect no fog formation, though the clear skies will make monitoring satellite imagery easy for fog detection and monitoring should fog actually begin to form.

MARINE

Issued at 200 AM EDT Fri Jun 26 2026

Generally calm conditions (i.e. no significant weather and winds of 20 knots or less) continue over Lake Superior today into Sunday morning as high pressure ridging remains settled overhead. However, as a PacNW low lifts from the Rockies this weekend into the Canadian Prairies early next week, expect the change in flow to allow shortwaves to begin moving over the Upper Midwest and Upper Great Lakes as early as Sunday. Therefore, expect to see winds increase from generally the east on Sunday, gusting up to 20 to 30 knots by the afternoon hours. In addition, expect the return of showers and thunderstorms, with a non-zero chance of severe weather possible early next week (there are serious doubts on whether this severe weather threat will materialize, but as for now the threat is at a non-zero chance given the hot and humid airmass moving overhead). Generally gusty east to south winds of 20 to 30 knots continue over the lake early next week until a shortwave low moving through on Tuesday potentially calms the winds down to 20 knots or less again behind it.

MQT WATCHES/WARNINGS/ADVISORIES

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