textproduct: Marquette

KEY MESSAGES

- Below normal temperatures continue through the rest of the workweek, with the warmest temperatures expected today and Friday.

- Tonight through Thursday morning brings periods of rain and thunderstorms, with the most active weather and rainfall expected in the west half.

- Warmer temperatures and greater moisture arrive late this weekend/early next week, potentially leading to additional rain showers and thunderstorms.

DISCUSSION

Issued at 249 AM EDT Tue Jun 23 2026

Mostly clear to partly cloudy skies continue the rest of this morning through most of today as weak high pressure ridging moving into the area precedes a weak Clipper shortwave moving through the Canadian Prairies and Northern Plains. As the Clipper approaches, expect to see cloud cover increase from the west late in the day, with rain showers starting up in the far west potentially just before sunset. There may be a shower or two that develops over the central U.P. late this afternoon/early this evening preceding the arrival of the Clipper as well thanks to diurnal heating supporting cu creation. However, thinking rain chances over the central right now for late this afternoon/early this evening are around 10 to 20% as not much forcing is evident; thinking if anything happens, it will need some help from the lake breeze(s) from Lake Superior, Lake Michigan, or both to get going (winds are expected to be light enough to support both lake breezes moving inland today). While there may be a couple hundred J/kg of CAPE in the atmosphere tonight, due to the lack of diurnal heating expect thunder chances to be under 25%. Expect the frontal forcing from the incoming Clipper to limit rain chances to the west half tonight, before the low passes by the area on Wednesday and spreads the rain chances across the rest of the Yoop. While we look to be mostly cloudy throughout the day on Wednesday, we could see some higher-CAPE air enter into the area (mainly the west half near Wisconsin); while certainly not expected given the light effective shear profile, a stronger thunderstorm or two cannot be completely ruled out at this time, particularly in the afternoon to early evening hours when diurnal CAPE is highest. Rain chances continue Wednesday night into potentially Thursday, although with the low exiting towards the St. Lawrence Seaway, expect the chances to dwindle with time as the distance between the low and our area increases. Overall rainfall- wise, some spots in the west could see over an inch of liquid between tonight and Thursday morning, especially in the heavier rain showers and thunderstorms. However, areas in the eastern half are projected to receive notably less rainfall, mainly between a tenth to half inch for the same time period. This is reflected well in the REFS probabilities for receiving over half an inch of rainfall; the running 24-hour probability is between 25-90% over the west half (excluding the northern Keweenaw), whereas the east half ranges from 0 to 40% (highest west/in the central).

In addition to the rain tonight into Thursday, expect below normal temperatures to continue through the rest of the workweek as antecedent cool air from Canada remains overhead, even as the Clipper passes by. Therefore, expect highs to be limited to the 60s to mid-70s today through Friday, with the warmest days expected today and Friday. It won't be until an upper-level ridge builds over the central CONUS this weekend that the antecedent cooler air is forced out and replaced by warm, moist Gulf air. As this occurs, expect the transition from below normal temperatures this week to above normal temperatures next week as highs transition into the 80s to potentially even lower 90s to round out the forecast period early next week. With a stout, vertically-stacked low lifting from the Northern Rockies early next week into the Canadian Prairies, we could see additional shower and thunderstorm chances move into our area via shortwaves rotating into the region, the first of which could arrive late this weekend/early next week. Given the higher moisture content and CAPE within the Gulf airmass, will need to keep an eye out on effective shear to see if stronger thunderstorms could be a problem for next week.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 123 AM EDT Tue Jun 23 2026

VFR conditions will prevail for the majority of the TAF period at all TAF sites. However, will introduce a PROB30 for MVFR conditions at IWD late in TAF period to account for rain showers in association with a low traversing the Upper Midwest. Otherwise, expect light and variable winds.

MARINE

Issued at 249 AM EDT Tue Jun 23 2026

Light winds of 20 knots or less continue today through tonight as weak high pressure ridging builds into the region. However, as a Clipper low skirts the area to the south on Wednesday, expect NE winds to increase to around 20 knots over the western lake during the day. Due to the weak Clipper low passing by the area, there could be a few thunderstorms over Lake Superior early this evening through Wednesday. As the low continues towards the St. Lawrence Seaway, expect the winds to slacken to below 20 knots, remaining that way until this weekend when the upper-level pattern across the Upper Great Lakes changes via a vertically-stacked low lifting from the Northern Rockies into central Canada; NE'rly gusts over 20 knots could be seen over the western arm by Saturday afternoon as the pattern shift occurs.

MQT WATCHES/WARNINGS/ADVISORIES

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