textproduct: Milwaukee/Sullivan

KEY MESSAGES

- There are 20 to 50 percent chances for showers and storms this evening toward central WI.

- A backdoor cold front Wednesday will bring gusty northeast winds behind it near the lake and cooler temperatures. This front will also bring chances for showers and storms (around 20 to 40 percent) Wednesday afternoon, with the better chances in south central Wisconsin.

- Dry for later this week into the weekend. with above normal temperatures developing.

UPDATE

Issued 625 AM CDT Tue May 26 2026

A very warm day with highs in the middle to upper 80s is still on track via swly winds, upper ridging, and plenty of sunshine. Thunderstorms are then expected to initiate along a weakening cold front over nrn WI late this afternoon. Weak wind shear and weak wly 850-300 mb flow will be present. The outflow boundaries from these storms will push swd and initiate additonial storms through the evening. Some of these showers and storms may eventually develop over MQT, Green Lake, Fond du Lac, and surrounding counties. The showers and storms will then dissipate from the late evening into the overnight.

Gehring

SHORT TERM

Issued 104 AM CDT Tue May 26 2026

Overnight through Wednesday night:

High pressure to the southeast of the area will continue to push east into today. Some middle level clouds will clip southeast parts of the area overnight, gradually pushing northward today. Another warm day is expected, with highs into the middle to upper 80s over most of the area including near the lake. Winds should shift southeast close to the lake by middle afternoon, which may bring cooler temperatures there.

Some diurnal cumulus clouds may occur this afternoon. Forecast soundings in northwest parts of the area are showing building elevated CAPE, but the area is capped to surface parcels, and any elevated upward motion should remain to the north and northwest. Thus, most CAMs suggest that any showers and storms remain to the north this afternoon, closer to the stationary front and within the southwesterly low level jet axis.

This activity may sag southward into northern parts of the area this evening and later tonight, as the front shifts southward as a backdoor cold front toward the area. There is some differential CVA passing through tonight, with forecast soundings trying to show some elevated CAPE up to 1000 J/kg or more in the late afternoon in northwest parts of the area, dropping quickly as the evening and night goes on.

For now, kept 20 to 50 percent chances for showers and storms going in the forecast over northern and northwestern portions of the area. Deep layer bulk shear is fairly weak, under 20 knots, so not expecting any strong to severe storms at this time.

The backdoor cold front should push south along the lake early Wednesday, then push further southwest over inland areas later in the day. There should be mean layer CAPE up to or over 1000 J/kg by late afternoon, with deep layer bulk shear around 20 knots or so. CAMs are all over the place with where showers and storms may develop, and there is not much besides the front to bring upward vertical motion.

For now, will maintain 20 to 40 percent chances for showers and storms in the afternoon on Wednesday over most of the area. The better chances will be over south central Wisconsin with the better instability.

Highs should reach the lower to middle 80s well inland, though this may depend on when the backdoor cold front moves through. Northern portions of the area may end up cooler if the front moves through sooner. It should remain in the 60s close to the lake with the increasing north to northeast winds. There should be cold air advection into Wednesday night to bring cooler temperatures to the area.

A moderate to high swim risk may occur later Wednesday into Thursday morning for the Lake Michigan beaches, with increasing north to northeast winds and building waves.

Wood

LONG TERM

Issued 104 AM CDT Tue May 26 2026

Thursday through Monday:

High pressure will slowly build southward into the region Thursday into Friday, bringing dry conditions and briefly cooler temperatures Thursday before highs rebound Friday. Cooler temperatures should occur near the lake each day. Another backdoor cold front may shift south/southwest across the area Friday night, as yet another high develops to the north of the region and shifts southward into the area over the weekend.

This is a result of the ridge axis remaining stout over the region into the northern Plains and south central Canada via 500 mb cluster analysis trends. This pattern should result in continued dry conditions into early next week, with temperatures warming gradually above seasonal normal values via ensemble member trends.

Wood

AVIATION

Issued 625 AM CDT Tue May 26 2026

VFR conditions today through Wed AM. Scattered showers and storms are expected toward central WI this evening.

Gehring

MARINE

Issued 104 AM CDT Tue May 26 2026

High pressure around 30.2 inches will continue to slowly move east of the region overnight into today. Breezy south to southwest winds will continue today, while high pressure around 30.4 inches is expected to build toward eastern Hudson Bay into Wednesday.

The high will eventually push a cold front southward over Lake Michigan tonight and Wednesday. Winds will quickly shift northeasterly behind the front and become gusty Wednesday into Wednesday night. Modest north to northeast winds should linger into Thursday.

A Small Craft Advisory may be needed Wednesday into Wednesday night for the nearshore waters for increasing north to northeast winds and building waves.

Another potential cold front may shift southward across the lake on Friday, as another high pressure system around 30.3 inches develops to the north of the region. This may bring another round of brisk north to northeast winds behind it.

Wood

MKX WATCHES/WARNINGS/ADVISORIES

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