textproduct: Marquette

KEY MESSAGES

- Temperatures remain above normal through Thursday. Widespread 80s are expected today, potentially getting into the lower 90s in portions of the the west.

- Slight risk of strong to severe thunderstorms this evening across Upper Michigan. Primary hazards are large hail and damaging winds.

- Marginal risk of strong to severe storms Thursday afternoon and evening in the south and east.

- Cooler and generally more pleasant weather in store this weekend into next week.

DISCUSSION

Issued at 244 AM EDT Wed Jun 10 2026

Most of the U.P. early this morning is becoming inundated with fog as marine fog off of Lakes Superior and Michigan move upslope onto land. After driving through some of it on my way to work as well as looking at webcam imagery across the Yoop, patches to potentially areas of the fog are looking dense (1/4 mile or less). Therefore, a Dense Fog Advisory remains in effect until late this morning (11 AM EDT). The only area left outside of the Dense Fog Advisory is the far west (i.e. Gogebic and Ontonagon counties); slowly increasing southerly downslopes winds with time today may keep dense fog from forming over there. Otherwise, it won't be until a weakening line of showers and storms moves through the western half of the U.P. just after sunrise this morning before we see the fog dissipate behind it.

Speaking on the convection expected today, the first round looks to move into the far west just after 12z/8 AM EDT this morning riding a weakening LLJ into the Yoop. No severe weather is expected with this round as diurnal CAPE aloft will be at its lowest and shear will be decreasing as the convection falls apart over the western half through the rest of the morning hours. However, as WAA moves overhead into the region behind the morning convection today, expect warm, moist air advected in from the Gulf to bring high temperatures into the 80s across the U.P., with some spots in the west potentially getting into the lower 90s. In addition, dewpoints look to shoot-up into the 60s across most of the area, with some spots potentially getting into the lower 70s by the mid to late afternoon hours. Taking also into account the PWATs being between 1.75 and 2 inches late this afternoon (which is at or above the 99th percentile of modeled climatology for our area), the atmosphere will have plenty of 'juice' (CAPE) to work with late today through tonight. In addition, shearing of 25 to 45 knots will help tilt the updrafts of the convection with height when it arrives late today through this evening, allowing for some long-lived thunderstorms to traverse the area. Therefore, we remain under a Slight Risk (15%+ chance) for severe weather today, with large hail followed by damaging winds being the main threats. In addition, while the environment is not favorable to it given that convection mainly does not look to be surface-based this evening, an isolated weak tornado cannot be completely ruled out (the chance is very low i.e. 2% to less than 5% according to SPC). With model soundings showing warm rain processes up to 13 kft and the anomalously high PWATs, there also remains a Marginal Risk (at least 5% chance) for excessive rainfall tonight for the west and central. Different CAMs generally show the 'main event' of convection starting between 20z this afternoon and 0z this evening. However, forecaster confidence on the timing and placement of the convection remains low at this point as the dying convection moving into the west later this morning is throwing a wrench into predicting when the showers and storms are moving in later this afternoon/evening. As the showers and storms roll through tonight, expect the severe potential and convective coverage to wane with time as the diurnal CAPE drops and the forcing weakens over the area; expect the last of the showers and storms out of the eastern U.P. by early Thursday morning.

Expect another warm day on Thursday, albeit with drier air in place as the greatest moisture will have moved east out of the area by that point. However, we can still expect high temperatures in the 80s across most of the U.P., with the warmest parts then being in the interior east. As a cold front pushes into the area from the west on Thursday, expect a shortwave low riding along the front to kick-off more showers and thunderstorms across the U.P. late in the afternoon through the overnight hours. While there will be a lot of shear to work with as the shortwave passes through, there won't be all that much CAPE. Therefore, the severe thunderstorm risk is rather low, with the SPC only highlighting the south central and eastern U.P. under a Marginal Risk (5% or greater chance) for severe hail and winds. Also, depending on how much rainfall falls with the convection this evening and late Thursday, there may be a spot or two that sees some flooding come late Thursday; thus, the WPC has the central and east under a Marginal Risk for excessive rainfall for Thursday.

Expect cooler temperatures behind the cold front from this weekend into next week as cool, dry interior Canadian air moves overhead. While a shortwave followed by another cold front could bring additional showers and thunderstorms to the area Friday afternoon and Saturday, expect drier weather overall as a low pressure spins from northern Ontario towards the St. Lawrence Seaway. Behind this low, ridging builds into the area early next week.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 656 AM EDT Wed Jun 10 2026

While generally VFR conditions hold over IWD most of the daylight hours today, some dying convection moving in after 12z could drop vis into MVFR or lower at times into the late morning hours. As for CMX and SAW, they look to struggle getting out of the FG/LIFR conditions, but slowly lift throughout the morning hours until finally improving to VFR by this afternoon. While there is a slight chance the dying convection makes it over CMX and SAW late this morning/early this afternoon, it is not expected to; some localized LLWS could be seen with the dying convection over the terminals this morning.

A second, more robust round of showers and storms looks to return to the TAF sites late this afternoon into this evening. With +TSRA possible, highly erratic and damaging winds as well as large hail could be seen. In addition, sharp vis and cig reductions as well as localized LLWS could be seen in the potentially +RA. While the convection will weaken and dwindle as it travels east out of the vicinity of the terminals late tonight, we could see flying conditions down into IFR or worse behind it; marginal LLWS is also possible behind the storms too.

MARINE

Issued at 244 AM EDT Wed Jun 10 2026

Dense marine fog continues over Lake Superior this morning, causing a Dense Marine Fog Advisory to continue across the area. However, as a line of dying convection rides WAA into the region this morning, we may see the fog dissipate over the lake today as anomalously warm, moist air moves overhead. However, should the warmer and more moist air mass actually intensify the marine fog, then the Marine Dense Fog Advisory will need to be extended in time (even despite the increasing winds at the sfc). By late this afternoon, expect showers and thunderstorms to begin moving into the far western lake, with some of the convection potentially being severe (SPC has us under a Slight Risk for severe weather); the main threats are large hail and damaging winds, although a rogue waterspout or two cannot be completely ruled out (despite the chances being very low i.e. around 2%). As the convection rolls in, expect the winds across the lake to increase to 20 to 25 knots by late this afternoon/early this evening from the E and SE, with the eastern side of the Keweenaw potentially flirting with 30 knot wind gusts at times. As the convection progresses eastwards tonight and begins to die down, expect the severe threat to diminish. In addition, expect the winds to become S and SW to generally 20 to 25 knots (with maybe some gusts up to 30 knots between Isle Royale and the Keweenaw). As a cold front starts to push in from the west on Thursday, expect winds to lighten across most of the area save for the area between Isle Royale and Thunder Bay, which could see SW'rly wind gusts of around 30 knots by the afternoon hours. With a shortwave low riding the cold front into the Upper Great Lakes late Thursday through Thursday night, we could see more showers and thunderstorms roll through the central and eastern lake; severe weather is not expected though due to the convection moving in during the overnight hours and the low CAPE projected during the event.

Behind the cold frontal passage and the shortwave low, expect the winds to pick up from the W to 20 to potentially 30 knots as CAA works over the area with the help of a shortwave rotating through the region. While the winds do appear to weaken to around 20 knots Friday night, another cold front pushing through on Saturday looks to bring W'rly winds of 20 to potentially up to 30 knots back across the area. With the cool and dry Canadian air remaining overhead through the rest of the weekend into next week, we could see winds gust up to above 20 knots once again on Sunday before ridging building in early next week brings calmer conditions to the lake.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Dense Fog Advisory until 11 AM EDT /10 AM CDT/ this morning for MIZ001-003>007-010>014-084-085.

Lake Superior... Dense Fog Advisory until 5 PM EDT /4 PM CDT/ this afternoon for LSZ162-244-245-263>267.

Dense Fog Advisory until 11 AM EDT /10 AM CDT/ this morning for LSZ240>243-247>251.

Dense Fog Advisory until 2 PM EDT this afternoon for LSZ246.

Lake Michigan... Dense Fog Advisory until 5 PM EDT this afternoon for LMZ221- 248-250.