textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Scattered thunderstorms, sub-severe, are expected north of I-94 through midnight.

- Active shower/storm pattern develops for Saturday night through Wednesday next week.

- A strong warming trend is expected early next week, potentially nearing Heat Advisory criteria Monday through Wednesday.

UPDATE

Issued 943 PM CDT Wed Jun 24 2026

The severe threat ended for the evening, but scattered storms are lingering north of I-94 with the wrap-around region of the weak low that is moving across northern Lake Michigan. This area of showers/storms will exit east central WI around midnight. There is still some instability and shear present, so a stronger storm or two cannot be ruled out. But overall, lapse rates have gone down and the CIN is increasing.

Cronce

SHORT TERM

Issued 117 PM CDT Wed Jun 24 2026

This afternoon through Thursday night:

As rain from this morning exits the southeast, watching the potential for new development that has begun along a boundary stretched largely west to east across the central forecast area. Instability will gradually increase this afternoon, with a few pockets of clearing within the widespread mostly cloudy conditions. Will also see a potential for storms to develop late afternoon into early evening along a weak cold front approaching from the northwest. Given surface based CAPE expected to increase to around 2000 J/kg (especially from Madison westward) along with 0-6 km bulk shear upwards of 40 kt, still thinking a few strong to severe storms will be possible this afternoon into the evening. The activity along the front may have a better chance to reach severe levels, given likely more available instability. Hail and wind remain the main severe concerns, though not out of the question for a tornado or two.

Will have to watch the potential for localized flooding concerns this afternoon and evening given a narrow swath of 1.5 to 3 inches of rain that fell this morning. If additional storms produce heavy rainfall over these already saturated areas, some localized areal or flash flooding could occur.

Showers and a few rumbles of thunder may linger mainly north of I-94 late evening as a surface low slowly moves through, with dry weather expected overnight behind the low.

A few showers will be possible mainly across the northeast half of the forecast area from late Thursday morning into early evening. This will be due to a weak vort max swinging through lingering cyclonic flow along with possible additional lift due to low level convergence as winds turn onshore near the lake. Not out of the question for a few rumbles of thunder as well. Otherwise, skies should be partly cloudy with highs in the 70s once again.

DDV

LONG TERM

Issued 117 PM CDT Wed Jun 24 2026

Friday through Wednesday:

The upper level flow is expected to be zonal on Friday, with upper level ridging beginning to build in from the west on Saturday. Dry weather is expected both days under surface high pressure. Temps will remain a bit below normal Friday, warming back to around normal Saturday as the upper ridge builds in.

Upper level ridging will continue to strengthen across the Midwest and Northeast United States early next week, with increasing temperatures likely for southern Wisconsin. Dewpoints will increase as well, with a chance for Heat Advisory conditions Monday through Wednesday, especially if it remains dry during the daytime periods. That said, there is a chance that storms could move through the top of the ridge and impact southern Wisconsin once or twice from Sat night through early next week. Confidence is on the lower end in any potential precip timing at this point.

DDV

AVIATION

Issued 524 PM CDT Wed Jun 24 2026

MVFR ceilings are prevalent across southeast WI. There is a break in the clouds over portions of southern WI as the first round of storms exits far southeast WI and a broken line of storms moves into central and south central WI. All hazards are possible with these storms, which includes damaging winds, hail, tornadoes, and flash flooding.

Expect clearing skies and light winds overnight.

Cronce

MARINE

Issued 117 PM CDT Wed Jun 24 2026

Weak low pressure around 29.9 inches in northern Minnesota will result in southerly winds across the lake today. As this system pushes eastward through northern WI this evening we expect winds to decelerate, turning east over northern portions of the lake and remaining south over the southern half. Showers and thunderstorms are expected at times today and tonight with the passage of this system.

Light northwesterly winds are expected Thursday as low pressure departs eastward. High pressure around 30.1 inches over Ontario and the western Great Lakes will dominate Friday through Saturday with light north to northeast winds likely. Sunday, low pressure deepens to 29.4 inches over the Central Plains, bringing breezy southeasterly winds to the lake. Winds turn southerly and strengthen into Monday as low pressure exits into the Canadian Prairies. On and off thunderstorms become more likely during this time.

DDV

MKX WATCHES/WARNINGS/ADVISORIES

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