textproduct: Milwaukee/Sullivan

KEY MESSAGES

- A backdoor cold front will pass from mid afternoon into the early evening with 20-40 percent chances for showers and storms.

- A High Swim Risk and Beach Hazard Statement is in effect tonight into early Thursday afternoon due to dangerous currents from onshore winds and high waves.

- A Small Craft Advisory is in effect tonight into early Thursday afternoon due to persistent northeast winds and high waves.

UPDATE

Issued 643 AM CDT Wed May 27 2026

A period of mid level clouds will continue this morning with the passage of a shortwave trough, then giving way to more sunshine and temps warming well into the 80s well away from Lake MI. For later today, a west to east upper trough axis over Ontario will track sewd into the nrn Great Lakes, then to the lower Great Lakes tnt. Surface ridging will build into the nrn Great Lakes behind this feature with the high settling over Lake Superior by 12Z Thu. The surface ridging will drive a backdoor cold front across srn WI and adjacent Lake MI from mid afternoon into the early evening. MLCAPE around 1000 J/KG is expected with little to no capping but also weak surface convergence. Isolated to scattered showers and storms (20-40 percent) are forecast from late afternoon into the early evening. The cold front and nely winds will then overtake all of srn tnt with cooler temps arriving.

Gehring

SHORT TERM

Issued 105 AM CDT Wed May 27 2026

Today through Thursday night:

An outflow boundary with modest north winds behind it continues to push south across southern portions of the area, and should exit to the south over the next few hours. A few weakening showers or storms may still clip far northern or northwestern parts of the area overnight. Otherwise, some middle to high clouds should continue to move through the area into Wednesday morning.

In addition, the backdoor cold front will move southward across Lake Michigan overnight into this morning, pushing southwest across the area later in the day. There is some question if this will push into and through the area earlier in the day, with gusty northeast winds behind it bringing in much cooler temperatures closer to the lake. There is some uncertainty with high temperatures on Wednesday, especially in northern and eastern parts of the area, if the front moves in sooner. For now, kept middle 80s well inland but have 60s along the shoreline and 70s in between.

The front will also serve as a potential focal point for isolated to perhaps scattered showers and storms by late afternoon on Wednesday, mainly over northern portions of the area, where the main upward vertical motion with the backdoor cold front approaches. Mean layer CAPE around 500 to 800 J/kg with weak capping and deep layer bulk shear around 20 knots or so may bring gusty winds and brief heavy rainfall with any stronger storms. Some CAMs are showing some activity moving southward into the area by early evening, with others keeping this just to the west of the area. So, still some uncertainty with where showers and storms may occur. Kept PoPs in the 20 to 30 percent range for the most part in northern parts of the area later this afternoon into early evening.

A Beach Hazards Statement for a high swim risk is in effect from Wednesday evening into early Thursday afternoon for the Lake Michigan beaches for Sheboygan, Ozaukee, Milwaukee, Racine and Kenosha Counties. Increasing north to northeast winds will bring building waves of 3 to 6 feet during this period. Life threatening waves and currents are expected. Stay out of the water, and away from dangerous areas like piers and breakwalls.

High pressure will push southward into the region later tonight into Thursday night. Brisk northeast winds tonight should bring cooler temperatures into the area for later tonight into Thursday, coolest near Lake Michigan. Lows tonight should drop to the lower to middle 50s. Highs Thursday should be in the 60s near the lake with middle to upper 70s well inland. Thursday night should be the coolest night, with lows in the upper 40s to around 50 degrees.

Wood

LONG TERM

Issued 105 AM CDT Wed May 27 2026

Friday through Tuesday:

Synopsis: Upper level ridging will gradually pivot/realign from an Upper Mississippi Valley - Canadian Prairies to an Upper Mississippi Valley - Hudson Bay axis this weekend into early next week, with large scale subsidence supporting mostly dry conditions and above normal temperatures across southern Wisconsin. Currently expecting the warmest day of the period to be Friday, when west southwest winds will be advecting a very mild air mass from the Great Plains into the region.

Temperatures will trend modestly cooler Saturday through Tuesday, as low level winds shift out of the east northeast, bringing a modestly cooler upstream air mass into the area. Despite the modest cool down, temperatures are still expected to remain above normal from the weekend into early next week.

Saturday through Sunday: Forecast remains dry through this portion of the period, but will need to be monitoring for possible backdoor cold frontal passages, given the change in larger scale wind pattern to east northeasterly/off of Lake Michigan. Lift along any such boundaries will be fighting an uphill battle against larger scale subsidence beneath the upper ridging, though some global ensemble members are hinting at light QPF during each afternoon period. Will thus be watching trends over coming forecasts and making PoP adjustments if necessary.

Quigley

AVIATION

Issued 643 AM CDT Wed May 27 2026

VFR conditions today into Thu morning. Isolated to scattered showers and storms are forecast late this afternoon and evening. Cigs of 5-6 kft are expected.

Gehring

MARINE

Issued 105 AM CDT Wed May 27 2026

A backdoor cold front is expected to push southwestward overnight into this morning across Lake Michigan, which will bring a quick north northeast wind shift behind it. Gusts up to 30 knots are possible along and behind this front over the open waters. Winds will remain north northeast through Thursday, gradually weakening Thursday night as high pressure around 30.2 inches builds into the Great Lakes region.

A Small Craft Advisory is in effect Wednesday evening into early Thursday afternoon for gusty north northeast winds behind the front and building waves of 3 to 6 feet.

A brief period of west to southwest winds over northern parts of the lake may occur Friday, with lighter winds to the south, as the high move slowly southeast of the area. An additional backdoor cold front later Friday night into Saturday morning will allow for brisk north to northeast winds once again through Saturday. Winds should then weaken and remain fairly light through early next week, under high pressure around 30.1 inches.

Wood

MKX WATCHES/WARNINGS/ADVISORIES

WI...Beach Hazards Statement...WIZ052-WIZ060-WIZ066-WIZ071- WIZ072...7 PM Wednesday to 1 PM Thursday.

LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...7 PM Wednesday to 1 PM Thursday.