textproduct: Marquette

KEY MESSAGES

- Showers and thunderstorms develop over the area today, persisting into Thursday morning. Greatest coverage of rainfall will be in the west half.

- Temperatures remain below normal until the end of the work week. The coolest high temperatures for the period are expected today.

- Above normal temperatures and increased humidity return early next week, along with periodic showers and thunderstorms.

DISCUSSION

Issued at 259 AM EDT Wed Jun 24 2026

The onset of rain early this morning has been delayed as the track of the frontal boundary associated with the incoming Clipper low ended up further south than previously anticipated. While this will eat into our rain totals for most of the area today into Thursday morning, we still may see a few heavier rain showers and thunderstorms today bring locally over an inch in some spots, mainly in the west where the mid-level low looks to move overhead. Thus, while the east could have some spots see only a few hundreths to locally up to an inch, the west half is still generally going to receive at least a tenth of an inch of liquid, with some spots locally receiving an inch or more. While mostly cloudy skies look to remain overhead today, with stronger lapse rates advecting into the mid to lower levels by this afternoon, we could see up to around 1 kJ of SBCAPE develop over the western half. That being said, with effective shear around 20 to at most 25 kts, no severe weather is generally expected, although SPC does highlight a Marginal Risk along and mainly just south of the U.P./WI border, particularly near Menominee which is technically within the Marginal Risk. Therefore, while severe weather is not expected across the area this afternoon and evening, we could see a sub-severe stronger thunderstorm or two that produces small hail and gusty winds over the U.P.

As the Clipper low leaves the Upper Great Lakes towards the St. Lawrence Seaway tonight into Thursday, expect the convection chances to dwindle with time tonight into Thursday, with most of the rain done by Thursday morning. Given the rainfall and incoming weak high pressure ridging from Canada to end the work week, some areas of fog could develop over the U.P. tonight before eroding away by the mid to late morning hours on Thursday; cannot rule out the fog being dense in spots as low temperatures tonight could drop into the mid 40s in the coolest areas. While the system rainfall does appear to be largely done by Thursday morning, diurnal heating and interaction with the Lake Michigan lake breeze boundary could produce some isolated light rain showers and non-severe thunderstorms near the Lake Michigan shoreline Thursday afternoon. As the aforementioned high pressure ridging builds in from Canada late this week, expect drier weather to move back over us as we start the weekend.

Expect the below normal temperatures to continue today through the work week; the coolest temperatures of the forecast period are expected today as highs become limited to the mid to upper 60s across most of the area. The exception where we could sneak into the lower 70s looks to be in the far east via warmer air wrapping around the Clipper low as it digs into the area. After today, expect the temperatures to progressively climb each day, although remaining below normal until the start of this weekend. As a mid to upper level PacNW low moves into the northern Rockies this weekend, it eventually lifts into the Canadian Prairies early next week. When it does so, expect above normal temperatures to finally return to Upper Michigan, with highs climbing into the 80s as early as Sunday. With the upper-level pattern connecting us with the warm, moist air in the Gulf, expect rain showers and thunderstorms to return as shortwave lows lift through the area from time to time next week. In addition, we could see highs get into the lower 90s by the end of the forecast period (around the middle of next week).

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 712 AM EDT Wed Jun 24 2026

VFR conditions this morning give way to deteriorating conditions as a Clipper low brings -SHRA and TSRA to the area today into this evening. With the arrival of the low along the WI border today, expect MVFR to occasionally IFR cigs to move over IWD today, with CMX and SAW remaining generally VFR unless a stronger SHRA/TSRA moves overhead. However, expect conditions to improve at IWD late this afternoon while SAW deteriorates down to MVFR as the low moves towards Lower MI. Moving into the overnight hours, expect cigs and vis to tank as some areas of fog potentially develop over the Yoop. Given the light winds developing tonight due to weak ridging building in from the north, thinking all of the terminals will drop down to LIFR late tonight; would not be surprised if we went down to airport mins or lower in some spots, especially if the fog materializes.

Winds are expected from the SE and E ahead of the low, while turning to the N behind it's passage today. By tonight, expect winds to become very light/calm.

MARINE

Issued at 259 AM EDT Wed Jun 24 2026

Light winds of 20 knots or less increase to E to NE gusts of 20 to 25 kts over the south central and western lake this afternoon as a Clipper low moves through the Upper Midwest today. This low may also bring some thunderstorms across the lake today. As the low continues towards the St. Lawrence Seaway tonight into Thursday, expect the thunderstorm chances and for the winds to slacken to 20 kts or less once again. However, given the expected rainfall over the lake today (as well as incoming weak high pressure ridging from Canada), some marine fog could develop over the lake tonight and continue into Thursday; some of the marine fog could be dense in spots. Will keep an eye on the expected vis conditions tonight into Thursday in case a Marine Dense Fog needs to be issued in the future.

Lake Superior looks to remain fairly quiet the rest of this week into this weekend, until we see an upper-level pattern shift via a PacNW low moving into the Northern Rockies this weekend before lifting into the Canadian Prairies early next week. As that occurs, a shortwave rotating around the upper-level low into the Northern Plains/Upper Midwest could increase E winds over the lake to 20 to 30 kts by Sunday.

MQT WATCHES/WARNINGS/ADVISORIES

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