textproduct: Marquette

KEY MESSAGES

- Mostly dry weather holds through mid week. Chances for showers and thunderstorms return for Thursday through Saturday (30-60% chance).

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

- Patchy dense fog over the far west this morning, particularly near the Lake Superior shores.

DISCUSSION

Issued at 323 AM EDT Tue Jul 28 2026

Early morning GOES WV imagery indicates the UP is now between a downstream trough moving to New England and a mid level ridge over the Rockies and Plains. At the sfc, weak high pressure is building overhead and will continue to hold influence over the Upper Great Lakes into Thursday. Nighttime microphysics indicate areas of dense fog over western Lake Superior which have intruded over parts of the western spine of the UP thanks to light northerly flow. These visibility impacts should dissipate shortly after sunrise as temps hold in the 50s. Meanwhile, a trough over the Pacific makes landfall late today, moving over the Rockies and flattening the mid level ridge Wednesday night into Thursday as it approaches the Great Lakes. With this increase in low level WAA, widespread temps climb into the low to mid 80s Wednesday and Thursday. The exceptions to this are the lakeshores on Wednesday, which remain in the 70s courtesy of lake breeze influences and a few interior western locations expected to reach near 90 on Thursday prior to trough and cold fropa Thursday night into Friday. This also reintroduces PoPs to the UP Thursday which continue into Saturday. While sufficient instability will be present for thunderstorms, bulk shear appears to be lacking to yield severe weather potential at this time. Quieter and warm conditions return for early next week as ridging once again returns to the region.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 725 AM EDT Tue Jul 28 2026

Lingering fog clears out in the first 1-3 hours of the 12Z TAF period, leaving VFR conditions the remainder of the period under the influence of high pressure. Strongest winds are expected at SAW at ~10 kts.

MARINE

Issued at 323 AM EDT Tue Jul 28 2026

High pressure ridging building in today allows for winds to largely remain below 20 kts lakewide, save for gusts ~20 kts at Whitefish Bay this afternoon where channeling is expected. This weak surface pattern the rest of the forecast package supports winds remaining below 20 kts until early next week.

Transient marine dense fog is the primary hazard for the short term forecast. Dense Fog Advisories will be allowed to expire over the east half at 12Z this morning as satellite imagery indicates widespread conditions of fog below 1 mile have dissipated. The west half will be extended through 15Z for now. Anticipate extending or reintroducing Dense Fog Advisories as fog persists into tonight.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Dense Fog Advisory until 11 AM EDT /10 AM CDT/ this morning for MIZ002-009.

Lake Superior... Dense Fog Advisory until noon EDT /11 AM CDT/ today for LSZ162- 240>244-263-264.

Lake Michigan... None.