textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Increasingly warm and still very low relative humidity days through Thursday.

- Increasing humidity and thunderstorm chances for late in the week.

SHORT TERM

Issued 214 PM CDT Mon Jun 1 2026

Tonight through Tuesday night:

The mid to high clouds have thinned this afternoon via differential AVA, but they will not completely dissipate until after the passage of a final lobe of vorticity that is rotating around the large upper trough to the east. That will occur this evening and will also be followed by 1030 mb high pressure building from Hudson Bay to over Lake MI by Tue afternoon. Thus, large scale subsidence is expected tnt-Tue with high temps on Tue ranging from the 60s at the Lake MI shoreline to upper 70s over south central WI.

A narrow upper ridge will then shift from the Upper MS River Valley and Lake Superior region on Tue to the lower Great Lakes by late Wed, while the sfc high moves to the lower Great Lakes and ern Ohio Valley. Light sly winds will return Wed to srn WI with temps warming into the lower 80s inland with 70s near the lake before the lake breeze develops.

Weak shortwave troughs will continue to roll the ridge toward the ern seaboard with swly winds and increased warm advection for srn WI. High temps for Thu are forecast to reach the middle 80s with an afternoon lake breeze developing near Lake MI.

Gehring

LONG TERM

Issued 214 PM CDT Mon Jun 1 2026

Thursday night through Monday:

An active weather pattern is still expected to develop for later this week. The first chance for precipitation continues to be Thursday night as a shortwave trough moves east from the Mississippi River Valley toward Michigan late Thursday into Friday morning, with activity dropping into Friday. The southwesterly winds from the Gulf will draw moisture into southern WI, contributing to increased instability through Friday evening and into early Saturday.

A slow-moving shortwave trough will make its way through northern WI Saturday afternoon, bringing a cold front/surface low and the potential for showers and thunderstorms, with some possibly becoming severe due to the moist air mass over southern WI. Initial forecasts suggest that 1.5"+ precipitable water values will be present during this time frame, increasing the risk of heavy rain.

Chances for showers/storms Saturday night into Sunday will depend on the position of the outflow boundary and frontal location. The shortwave trough is expected to move east, followed by shortwave ridging into WI, but continued high humidity/temperatures could create small chances for showers or storms.

Beyond Monday, the upper ridge is expected to remain over southern WI and the Great Lakes, with continuing high humidity/temperatures.

AVIATION

Issued 214 PM CDT Mon Jun 1 2026

VFR conditions this afternoon through Tue and Wed.

Gehring

MARINE

Issued 214 PM CDT Mon Jun 1 2026

High pressure around 30.4 inches over Hudson Bay will move to Ontario and Lake Superior by early Tuesday morning, then south over Lake Michigan for Tuesday afternoon and night. Expect light to modest north to northeasterly winds this afternoon to turn more easterly late tonight, but back to northerly on Tuesday. Light and variable winds are then forecast later Tuesday and Tuesday night.

Light to modest southerly winds will then return to Lake Michigan for Wednesday and Wednesday night as the high slowly moves east of the region. Winds are expected to gradually increase and shift more southwesterly for Thursday afternoon and night as low pressure around 29.7 inches tracks east across Ontario. Accompanying the late week system will be chances of showers and storms that will continue into the weekend.

Gehring

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...None.