textproduct: Marquette

KEY MESSAGES

- Benign weather with cooler than normal temperatures is expected the rest of this week.

DISCUSSION

Issued at 258 PM EDT Mon May 4 2026

Upper air pattern consists of deep cutoff lows over northern Ontario and central CA with ridging stacked on top of the CA low and over Mexico with mostly zonal flow over much of the eastern 2/3 of the CONUS. This is a quite blocky pattern that will result in a stagnant weather pattern in the near term.

For the remainder of today, the cold front from the near 982 mb surface low over northern Ontario will continue to push through and bring showers to the eastern UP this afternoon. An isolated thunderclap or two cannot be ruled out in the far southeast (and LightningCast has presented some locations of ~10% lightning probs early this afternoon), though no lightning has been observed yet. Clearing skies have already been observed in the west behind the front, though upstream, some remnant fair weather cu is observed. Partly cloudy skies, especially in the interior west, will allow for temperatures to fall to near- or sub-freezing tonight. Wind gusts, which are as high as 48 mph at CMX, will decline below 20 mph overnight except for at the immediate lakeshores of Lake Superior.

With the blocky weather pattern featuring the major surface pressure systems far away from the Great Lakes, the dominant feature will be the surface high that sets up over the Plains as the block is displaced slightly east and southeast. This sets up mostly benign weather conditions over the UP through early Thursday morning, and even with the potential for a weak shortwave to bring showers Thursday, NBM PoPs are sub-20. Fire weather will be worth keeping an eye on in spite of high temperatures remaining 60 degrees or less. RHs are forecast to dry out to the 30s% range in the interior and locally into the 20s% range along the state line, though the presence of winds hazardous to fire weather is somewhat unknown, as the deterministic NBM forecast suggests PM wind gusts regularly near or in excess of 15 kt, though the LREF joint probabilities of 15 mph winds and sub-30 RH is less than 10%. It may be some time before our next widespread chances of precipitation, as this pattern is showing no clear signs of breaking up, and the next time the LREF shows widespread chances of over 0.1 inches of precip in a day in excess of 25% is not until the 13th.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 716 PM EDT Mon May 4 2026

VFR conditions prevail through the TAF period. A broad trough over the Great Lakes will continue to bring colder air into the region and maintain gusty northwesterly winds. As cold air aloft strengthens on Tuesday a few very light rain or snow showers can't be ruled out but not expecting any impactful vsby or cig restrictions. Winds gusting to 40kt this evening at CMX will weaken by late evening but still remain gusty through much of Tuesday.

MARINE

Issued at 258 PM EDT Mon May 4 2026

Gusty southwesterly to westerly winds continue this afternoon and evening, with gusts to near 35 kt especially in the nearshores just to the north of the Keweenaw Peninsula. Winds fall to near 25 kt around midnight, lingering between 20-25 kt until Tuesday night. With the major pressure systems remaining far away from the Upper Great Lakes, wind gusts should remain sub-20 kt for the remainder of the week and the weekend. Waves will slowly subside through tonight and Tuesday, first falling below 8 ft after midnight, below 5 ft by Tuesday evening, and then below 3 ft by Wednesday morning.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... Gale Warning until 8 PM EDT this evening for LSZ243-244-264- 266.

Lake Michigan... None.