textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Mostly dry weather under high pressure expected through Wednesday. Fire weather concerns may increase early in the week. Cooler by Lake Michigan with a lake breeze each day.

- An unsettled weather pattern is expected for late next week.

SHORT TERM

Issued 1157 PM CDT Sat May 30 2026

Rest of Tonight through Tuesday:

Light east winds overnight will transition to southeast by late morning as high pressure sits over the Upper Great Lakes and low pressure starts to develop in the Northern Plains. A broad area/long line of thunderstorms that currently stretches from eastern Montana to western Nebraska and central Kansas will progress east-northeast overnight into Sunday morning along the nose of the low level jet and a mid level shortwave trough.

There is a small chance (20%) that the outflow boundary from this storm complex could fire off more storms in Iowa Sunday afternoon that could make it into southwest WI Sunday night. In addition, the upper level feature (weak vorticity advection) is producing light rain/sprinkles over MN this evening and that forcing is going to translate over WI Sun evening, so we may need to increase precip chances. Overall the forcing for storms is weak for WI, but with the daytime heating and a subtle moisture return of dewpoints in the lower 50s, the envirnoment could support some ongoing/decaying storms. If anything makes it here, it would quickly diminish as it treks east through southern WI due to the dry air and high pressure in control.

A similar scenario is possible for Monday. But also on Monday, the upper low sitting over the northeast will swing a trough into Michigan. This will push colder, lake-cooled air from east to west across southern WI Monday morning (back door cold front). This one does not look as strong as the one today (Saturday), but we can still plan for a steady easterly wind and cooler temperatures. Tuesday winds will be lighter but with similar temperatures.

Cronce

LONG TERM

Issued 1157 PM CDT Sat May 30 2026

Wednesday through Saturday:

The high will begin to shift eastward Wednesday, so inland temps closer to 85 are expected, but there will still be a lake breeze. With winds shifting to the southwest on Thursday, the lake breeze will be much weaker/delayed, so highs will range from the upper 80s inland to the upper 70s lakeshore.

The shifting weather pattern should allow for some much-needed rain to return to southern WI late in the week. There is still a lot of uncertainty here, so the extended forecast will continue to feature general chances for storms (20 to 40%) for the whole period. We will have to wait a few more days for timing and rainfall amounts to become clearer.

The pattern is a little complicated and therefore uncertain in the extended. A potent mid level shortwave trough will track along the U.S./Canadian border Wed night and Thu (speed is very different between models). Meanwhile, a weak shortwave is expected to ripple from the southern Plains into the Upper Midwest and help "feed" moisture into that US/Canada low and bring a chance (20-40%) of rain to southern WI Thu nt. If there are timing differences with the northern low and the southern Plains shortwave, then the rain may not pan out for us or be very light.

However, it looks like there will be another round of these shortwaves colliding over the Upper Midwest again Friday night into Saturday, and therefore another chance for rain. We are going to be very warm and relatively humid (dewpoints in upper 50s) from Friday through Sunday. This will be conducive for thunderstorms with any forcing we can get from shortwaves. While this does not look like a really great setup for severe storms, we will have to watch for the potential for a few at times.

Overall, we should see some rain between Fri and Sun but the models seem to be producing too much QPF (precip) at this time.

Cronce

AVIATION

Issued 1157 PM CDT Sat May 30 2026

VFR through the TAF period with high clouds overhead. Winds will gradually decrease through the night and be lighter tomorrow out of the southeast. Expect the lake breeze to temporarily cause a brief uptick in the winds.

Cronce

MARINE

Issued 1157 PM CDT Sat May 30 2026

High pressure over the Upper Great Lakes will strengthen to around 30.2 inches overnight and continue to dominate the weather pattern through Tuesday. Lighter winds are expected Sunday. Then breezy easterly winds will return Monday into Monday night before weakening for Tuesday. Winds are to become more southerly on Wednesday as the high pressure breaks down and exits the region while low pressure develops over the Plains. Look for increasing southerly winds Thursday as low pressure of 29.7 inches crosses the Northern Plains.

Cronce

MKX WATCHES/WARNINGS/ADVISORIES

WI...None LM...None