textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Chances for showers and thunderstorms (30 to 50 percent chances) remain for Monday afternoon and evening, as a cold front moves through the area. Gusty winds could occur with stronger storms.

- Warmer and breezy Monday, then cooler the rest of the week.

- Frost may occur toward the middle to later portions of the week.

UPDATE

Issued 557 PM CDT Sun May 3 2026

A wind shift boundary will move southeast through the area this evening, with gusty southwest winds weakening and becoming west. The showers and storms with the better upward vertical motion north of the area should remain there into the evening. Thus, kept the forecast dry. Mostly clear skies tonight are expected, with lows in the middle 40s.

Winds will become gusty again out of the southwest Monday morning until the cold front pushes through the area later Monday afternoon into Monday evening. Warm temperatures in the middle 70s are expected Monday ahead of the front, even near the lake with the gusty southwest flow.

CAMs still show scattered showers and storms (30 to 50 percent chances) developing along the front in the late afternoon and pushing through into the evening hours. There is decent upward vertical motion from frontogenesis response in the low levels. Forecast soundings showing around 500 to 800 J/kg of skinny mean layer CAPE in the afternoon, with deep layer bulk shear of 35 to 45 knots. There may be gusty winds that occur with any stronger storms, with the dry air in the low levels.

Some showers may linger overnight into Tuesday in southern portions of the area, though the cold air advection on northwest winds may help to dry things out and keep more of this to the south.

Wood

SHORT TERM

Issued 121 PM CDT Sun May 3 2026

Tonight through Monday night:

Given quick clearing behind this morning's rain, high temperatures should rise in the upper 60s to low 70s this afternoon amid good solar insolation and warm advection on southwesterly surface winds. A cold front is then expected to move over the area tonight, causing breezy southwesterly winds to ease for a bit and become westerly.

Southwesterly winds then increase again after midnight and another shot of surface warm advection is anticipated into tomorrow on breezy winds ahead of another cold front. Highs will rise into the low to mid 70s. The cold front is expected to move south into our CWA during the mid afternoon and move to the WI/IL border into the evening. Models continue to suggest that the environment preceding this front will be starved of moisture, leading to skinny CAPE profiles, high based storms, and widely scattered storm formation along the front. As such, activity will be hit or miss during the afternoon. If a stronger storm does manage to get going, gusty winds would be the main threat as these storms rain into the dry near surface environment.

Thunderstorm activity may largely wrap up by 8-9 pm but some post frontal fgen may cause some lingering scattered rain along the WI/IL border Monday night into Tuesday as the front slows it's southward progression in northern Illinois.

CMiller

LONG TERM

Issued 111 PM CDT Sun May 3 2026

Tuesday through Sunday:

Models continue to advertise much of the same from yesterday's long term forecast for the extended period.

Following the front, a cooler patter returns Tuesday through Thursday as a large trough dips into the Great Lakes region. Tuesday may feature some showers along the Wisconsin/Illinois border as the northern periphery of 700mb fgen clips the border area. Daily highs will be in the mid to upper 50s. Wednesday looks relatively dry as some mild surface pressure rises occur over the upper midwest, but Thursday does look like the best day for shower activity at this time as the base of the upper level trough rotates through the area. Frost potential will also return Tuesday night through Thursday night, with the most widespread potential on Wednesday night into Thursday morning.

Temperatures then begin to warm Friday into Saturday as ridging builds over the plains. The deterministic runs of the GFS and ECMWF suggest a few weak WAA waves may cause nebulous shower chances Saturday.

CMiller

AVIATION

Issued 557 PM CDT Sun May 3 2026

A wind shift boundary will move southeast through the area this evening, with gusty southwest winds weakening and becoming west. The showers and storms should remain north of the area into this evening. Thus, kept the forecast dry. Mostly clear skies tonight are expected.

Winds will become gusty again out of the southwest Monday morning until the cold front pushes through the area later Monday afternoon into Monday evening.

Scattered showers and storms (30 to 50 percent chances) are forecast along the front in the late afternoon and pushing through into the evening hours. There may be gusty winds that occur with any stronger storms. Ceilings should remain in the 6000 to 8000 foot AGL range during this time.

Some showers may linger overnight into Tuesday in southern portions of the area, though northwest winds behind the front may help to dry things out and keep more of this to the south.

Wood

MARINE

Issued 111 PM CDT Sun May 3 2026

A weak cold front is expected to pass over the lake this evening, easing winds for a time before winds return to a southerly direction and become gusty again around dawn on Monday. Winds will then increase Monday morning ahead of another cold front in association with low pressure of 28.9 inches, and a short 6 hour period of Gales is anticipated over the northern third of Lake Michigan between 10am and 4pm CDT. A Gale Warning has been issued. Winds then ease through the afternoon from north to south over the lake as the cold front moves south. Winds behind the front will become northwesterly.

The pressure gradient will then ease over the lake Tuesday through Thursday, with light persistent west to northwest winds occuring. Light and variable winds may briefly occur at times as various weak surface ridges move west over the lake.

CMiller

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...Gale Warning...LMZ261-LMZ362-LMZ364-LMZ563...10 AM Monday to 4 PM Monday.

Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 7 PM Sunday.