textproduct: Marquette

KEY MESSAGES

- Smoke from upstream wildfires will continue to impact Upper Michigan into this weekend. Air Quality Alerts remain in effect today. Consider limiting strenuous outdoor activity or remaining indoors when possible.

- Dry weather is expected through the remainder of the weekend. Widespread precipitation chances return Monday, including potentially strong to severe thunderstorms.

DISCUSSION

Issued at 341 AM EDT Sat Jul 18 2026

Early morning GOES satellite imagery reveals an upper level trough axis descending southeast through the Upper Great Lakes and the attendant surface low pressure skirting along the NE Lake Superior shorelines. A weak cold front is noted having largely crossed the UP though temps remain in the 60s to 70s area wide as surface dewpoints remain just as high. Some patchy fog may be present through day break given ample moisture, however, an uptick in breezy NW winds will likely prevent areas of widespread dense fog. Increased ridging aloft and large-scale subsidence will be the rule today through the rest of the weekend, keeping the area dry. Unfortunately, hrrr/rrfs smoke models continue to highlight the return of moderate to dense smoke concentrations this afternoon, lingering through Sunday. The Michigan Dept of Environment, Great Lakes, and Energy (EGLE) has maintained the statewide Air Quality Alert through today, and it would not come as a surprise if this was further extended into Sunday. It is reasonable to expect at least some smoke impacts into the early part of next week given continued northwest flow, though hopefully at lower concentrations than in recent days given yesterday's rainfall over the upstream wildfires. High temperatures should be a bit on the cooler side today under breezy northwest flow, especially closer to Lake Superior where upper 60s to low 70s will be found. Further south and west, mid 70s to near 80 will be common. As high pressure settles southeast into the Lower Great Lakes on Sunday, light return flow might make for a slightly warmer day albeit moderating close to Lake Michigan instead.

Widespread rain and thunderstorm chances return Monday into early Tuesday as a shortwave rounds the northern periphery of a stout ridge over the western half of the conus. This shortwave then deepens as it descends southeast from western Ontario into the Great Lakes. Ample moisture advection ahead of a developing surface low pressure will contribute to a favorable environment for possible severe weather sometime Monday into early Tuesday. SPC has introduced a day 3 Slight Risk (level 2 of 5) for severe weather. those with outdoor plans early next week should continue to monitor the forecast for updates.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 124 PM EDT Sat Jul 18 2026

MVFR to IFR conditions will be the rule today as wildfire smoke is advected back south by gusty N to NW flow. NW wind gusts up to 15- 20kts at CMX and SAW fall back late this afternoon into the evening. As high pressure settles over the Great Lakes tonight into Sunday, confidence is low that conditions will improve, though smoke may become more patchy Sunday afternoon as winds shift to the SW.

MARINE

Issued at 341 AM EDT Sat Jul 18 2026

Improved visibility has been noted on areas webcams as a cold front moved through the area early this morning, however, two marine hazards are expected to develop today. The first being gusty NW winds largely east of the Keweenaw Peninsula. Small Craft Advisories remain in effect for marine zones between Marquette County to Whitefish Point where NW gusts between 20-30 kts will be common along with significant wave heights between 3-5 ft. These conditions fall off this evening as high pressure settles overhead into Sunday. The other marine hazard will be the return of dense wildfire smoke advected back over Lake Superior this afternoon. While there is some uncertainly how low visibility may fall, opting to continue the Marine Dense Smoke Advisories across the eastern 2/3rds of the lake.

Looking ahead, impactful marine weather is becoming increasingly likely Monday through Tuesday as a deepening low pressure translates through Ontario, bringing strong lakewide 20-30 kt southwesterlies ahead of the system Monday and potential Gales behind the subsequent cold frontal Tuesday. Latest model guidance shows some disagreement with said Gale potential, with the latest NBM a bit more bullish (50- 75% chance) and EC >20%. In addition, severe storms are becoming increasingly likely along and or ahead of the cold front. Continue to monitor the forecast over the next few days as details become clearer.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Beach Hazards Statement until 10 PM EDT this evening for MIZ005-006.

Lake Superior... Dense Smoke Advisory until 8 PM EDT /7 PM CDT/ Sunday for LSZ240>251-263>267.

Lake Michigan... Dense Smoke Advisory until 8 PM EDT Sunday for LMZ221-248-250.