textproduct: Marquette

KEY MESSAGES

- A warming trend early this week may cause increased heat risk for vulnerable and sensitive populations. Highs in the 90s are possible near the stateline on Tuesday.

- Thunderstorm chances (15-30%) persist in the forecast through Tuesday as multiple disturbances move through; however, confidence is low due to the 'pop-up' nature of the convection.

- Dry weather returns on Wednesday, likely persisting into the weekend.

DISCUSSION

Issued at 106 PM EDT Mon May 25 2026

Warmer temperatures are expected today as the WAA last night and mostly sunny skies will allow highs to get into the 80s across much of the interior area today. With the fog dissipating over the U.P. this morning, highs are expected to get into the 70s even over much of the interior east today despite the onshore flow from Lake Michigan limiting temperatures into the 60s by the lakeshore. With high pressure ridging over the Lower Great Lakes today shifting towards New England and troughing set up over the Plains, southwest flow is expected throughout the day today, with gusts up to around 20 mph possible by the mid to late afternoon hours. While sunny skies are being realized today (as seen by satellite imagery), given that we have PWATs around 1" over the U.P. today, thinking RHs will generally remain at or above 30% throughout the day. That being said, some spots in the interior west look like they will sneak into the upper 20 percents due to strong mixing in the boundary layer thanks to the solar heating from the cloud-free skies. While some CAMs do show some convection firing over the central U.P. late this afternoon, thinking the rain chances will remain low due to the spotty, 'pop-up' nature of the convection as well as convection already being seen in Wisconsin this morning potentially 'eating away' any potential atmospheric energy that could be used upstream over us. Therefore, limiting rain shower and thunderstorm chances to around 15 to 30% late this afternoon into this evening over the central U.P. Convection associated with a cold front moving through the Arrowhead of MN this evening could also bring some showers and thunderstorms across mainly the western half of the U.P. tonight. However, given that the placement of the front is further north (we are only being skimmed by the cold front) and the convection would need to pass through the stable sfc marine layer of Lake Superior as instability is progressively lost aloft due to diurnal cooling, thinking the chances for showers and thunderstorms tonight are low (15-25% chance). Nevertheless, as stated by the mid shift, convection moving down from the northwest to the southeast over us does tend to overperform what guidance suggests, even though we have been taken out of the Marginal Risk by SPC earlier this morning. Thus, we may need to keep an extra eye on the convection moving towards the western U.P. late tonight in case some marginal severe winds and/or hail become realized.

The warmest weather of the week looks to arrive on Tuesday as zonal flow aloft allows for sunny skies once again across the area, with highs looking to get into the lower 90s in the interior areas along the Wisconsin border. The warm weather may increase heat risk concerns for some of the more vulnerable portions of the population; be sure to drink plenty of water, and don't overwork yourself outside, especially during the hottest hours of the day. Some pop-up showers and storms could form along the Wisconsin border during the afternoon, but expect the convection to be non-severe. While RHs look to be lower on Tuesday, potentially below 25% over the interior west (around a 30 to 50% chance according to the latest REFS run), with winds looking to remain light at less than 15 mph, no elevated fire weather conditions are expected.

From Wednesday onwards, expect dry conditions to continue as an omega block sets up over the central CONUS. While some cooler air from the eastern half of Canada looks to dive in overhead during much of the rest of the forecast period (the last half of this week through next weekend), given the dry conditions allowing for sunny skies throughout most of the period, expect near to above normal temperatures to continue during the daylight hours (highs in the 60s to 80s). In addition, given the light sfc flow caused by the the omega block, expect the influence of the lake breeze to become more notable in ensuing days via the lack of synoptic-scale flow. With winds generally staying 20 mph or less, no elevated fire weather conditions are expected throughout the period, even despite the warm temperatures and min RHs dipping to 30% or less the last half of this week through next weekend.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 746 PM EDT Mon May 25 2026

Radar shows a few thunderstorms confined to Alger County and points east as of 00z Tue. Expect this activity to remain east of the terminals and continue to trend down over the next 1-2 hours with the loss of daytime heating. This leaves VFR conditions across Upper Michigan tonight under mostly clear skies aside from some patchy high cirrus. A cold front over northern Minnesota will approach from the northwest this evening, bringing a renewed chance for a few showers in the west. Will carry PROB30s for -SHRA at KIWD and -TSRA at KCMX prior to 06z. Meanwhile, a southwesterly LLJ ahead of the front will bring some LLWS to KCMX and KSAW overnight. Otherwise expect VFR conditions through the end of the period with winds turning N-NW at 5-10 kt on Tue behind the front. Can't rule out another round of scattered showers and perhaps thunderstorms Tuesday afternoon, but chances are too low to include in the TAFs for now. Highest probs will exist near the WI border.

MARINE

Issued at 106 PM EDT Mon May 25 2026

With the marine fog now dissipated and out of the area (except in the far north along the Canadian shoreline), expect the light winds of 20 knots or less today to rise to southwest winds of 20 to 25 knots tonight over mainly the central and eastern lake ahead of a cold front skimming the region. While we may see a couple of showers and thunderstorms along the south shore near Marquette late this afternoon into this evening, and again with the cold front passing by tonight (mainly over the central lake), given the 'pop-up' nature of the convection and the better forcing of the cold front remaining further north, rain/thunderstorm chances remain at 30% or less over the next 24 hours. Once the cold front passes by and weak zonal flow takes its place, expect light winds of 20 knots or less to return on Tuesday. The light winds remain until potentially Wednesday, when a dry cold front brings northeast winds of around 20 to 25 knots across the western lake. With a high pressure ridge setting up shop over the central CONUS the rest of the week, expect winds to remain 20 knots or less throughout the rest of this week into this next weekend.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Beach Hazards Statement until 10 PM EDT this evening for MIZ014.

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