textproduct: Milwaukee/Sullivan

KEY MESSAGES

- A backdoor cold front will continue to move southwestward into the area into early evening, accompanied by a broken line of showers and storms. Any storm toward northwest parts of the area may produce strong winds and hail. These showers and storms should gradually weaken by middle to late evening as they sag southward.

- 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 705 PM CDT Wed May 27 2026

A broken line of showers and storms will continue to sag southward into northern portions of the area into this evening, along a backdoor cold front. There may be strong winds and hail with any storms in northwest parts of the area, where mean layer CAPE between 500 and 1000 J/kg and deep layer bulk shear of 25 to 30 knots reside. This activity should gradually weaken by middle to late evening as it sags further southward, as instability weakens with the loss of daytime heating.

After the showers and storms end and the backdoor cold front shifts southwest of the area, northeast winds will steadily increase by later this evening and overnight, lingering into Thursday. This will bring clearing skies overnight into Thursday, as the high pressure system shifts southward into the region. Lows tonight should drop into the lower to middle 50s, with highs Thursday in the 70s inland with 60s closer to Lake Michigan.

Wood

SHORT TERM

Issued 318 PM CDT Wed May 27 2026

Tonight through Thursday night:

A backdoor cold front will sag southwestward through the region between 5 PM and 9 PM CDT, with isolated to scattered rain and storms along the front during this time frame. The frontal boundary will become enhanced by the cold Lake Michigan waters, allowing it to press inland rapidly this evening into CAPE of 1000-1500 J/kg. There is a potential for low-level CIN to build into the area ahead of the front as temperatures begin to cool this evening, which could inhibit shower and storm development. That being said, almost all meso models do show a cluster of storms developing along the front, and a few of these have already begun to develop in northern Wisconsin. If the front moves faster than the developing CIN, we likely see a broken line of gusty showers moving northeast to southwest. A few cells that grow tall enough may become capable of producing damaging winds, but the potential is low at this time. SPC has a marginal risk across just central Wisconsin for this potential.

Any lingering thunderstorms will taper off into the overnight hours, becoming light showers then ending completely by midnight. Northeasterly winds are expected behind the front, gusting 20-25 mph and bringing lows in the mid to low 50s. A Beach Hazards Statement is in effect for rising waves and dangerous currents along the Lake Michigan shoreline tonight into Thursday morning. Stay out of the water, and away from dangerous areas like piers and breakwalls!

Dry conditions continue through Thursday, with northeasterly winds expected throughout the day. Gusts to 20 mph will linger near Lake Michigan into far southern Wisconsin, with all winds gradually diminishing overnight. With northeast winds off the lake, expecting lower high temperatures in the 70s to perhaps 80 degrees inland, and in the mid to upper 60s east of the Kettle Moraine. Overnight Thursday, lows in the upper 40s are expected.

MH

LONG TERM

Issued 318 PM CDT Wed May 27 2026

Friday through Wednesday:

High pressure will keep winds light and allow temperatures to rise back into the 80s in most places on Friday, with highs in the low 70s along the Lake Michigan shoreline as a lake breeze develops in the afternoon hours. Friday night, an additional backdoor cold front will sweep southwestward, bringing a very low chance of showers (NAM with a known moisture bias being the core model showing shower development) to central Wisconsin overnight. Expect lows in the mid 50s.

Saturday, light easterly winds will keep southeastern Wisconsin in the 70s, and will allow southwestern Wisconsin to rise into the 80s. High pressure will build into the Great Lakes and allow for light winds and plenty of cooling overnight into the low 50s to upper 40s. Sunday will see highs similar to Saturday as high pressure lingers across the region, with continued dry conditions through the day. As high pressure migrates southward, an additional back door cold front will bring the next low chances (~15%) for showers and storms Sunday night into Monday morning. An isolated shower or two may linger into Monday.

Tuesday, low pressure develops in the central High Plains and brings in southeasterly winds by Wednesday, bringing temperatures back up into the 80s on Wednesday. Chances for rain and storms may develop again into Wednesday as low pressure begins to eject.

MH

AVIATION

Issued 705 PM CDT Wed May 27 2026

A broken line of showers and storms will continue to sag southward into northern portions of the area into this evening, along a backdoor cold front. There may be strong winds and hail with any storms northwest of Madison. This activity should gradually weaken by middle to late evening as it sags further southward, as instability weakens with the loss of daytime heating.

Added PROB30 groups for Sheboygan and Madison for a thunderstorm with briefly reduced visibility until middle evening, though not sure if these sites will be affected. Kept mention out of rest of terminals for now, as not confident this precipitation will reach the rest of the area.

After the showers and storms end and the backdoor cold front shifts southwest of the area, northeast winds will steadily increase by later this evening and overnight, lingering into Thursday. This will bring clearing skies overnight into Thursday, as the high pressure system shifts southward into the region.

Wood

MARINE

Issued 318 PM CDT Wed May 27 2026

High pressure around 30.3 inches will continue to build southward into the Great Lakes this evening through tonight, bringing a cold front southward through tonight. Behind this front, gusty northerly winds will produce waves and winds hazardous to small craft in nearshore waters, with gusts around 25 kt expected. Winds will gradually diminish through Thursday, with hazardous conditions diminishing midday. High pressure remains in place through the weekend, with a few additional weak cold fronts bringing brisk northeasterly winds Friday night and Sunday night. High pressure generally remains in place through early next week, with light and variable winds expected.

MH

MKX WATCHES/WARNINGS/ADVISORIES

WI...Beach Hazards Statement...WIZ052-WIZ060-WIZ066-WIZ071-WIZ072 until 1 PM Thursday.

LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 1 PM Thursday.