textproduct: Milwaukee/Sullivan

KEY MESSAGES

- 40-60 percent chances for showers toward the IL border tnt with slight chances for thunderstorms over the MKE metro area and far srn WI this evening.

- Below normal temperatures for early next week.

- Next chances for thunderstorms develop Tuesday and Wednesday next week. Too early to tell intensity, but monitoring for potential stronger storms.

- Active weather pattern continues into next weekend.

UPDATE

Issued 740 PM CDT Sat Jun 13 2026

Lowered rain chances for tonight. Cumulus development along the diffuse cold front over the MKE metro area has actually increased but a lack of vertical depth remains. There is however isold shower development along this boundary over nw IL. Will maintain only slight chances for thunder this evening with the passage of the weak cold front.

Otherwise decaying and high based showers are attempting to move across Lafayette and Green Counties but there is no ground truth at this time. Weak 850-700 mb frontogenesis will continue across far srn WI much of the night as the upstream shortwave trough over the Dakotas does not move across srn WI until after 12Z Sun. Any showers that do occur will likely be high based and relatively light. Nwly sfc winds and cold advection will increase after midnight as the upper wave approaches from the west with cold advection continuing into the early afternoon. Broken stratocumulus is expected to develop by late morning and last into mid afternoon. Thus high temps only in the upper 60s are forecast.

Gehring

SHORT TERM

Issued 244 PM CDT Sat Jun 13 2026

Tonight through Sunday night:

A cold front is currently draped from southwestern Wisconsin to northeast Wisconsin. This front is expected to gradually move southeastward through this evening, triggering scattered showers and thunderstorms (40-60% coverage). Ahead of the front, isolated showers (~20% coverage) and southwest winds gusting up to 35 mph are expected. Excess cloud cover from an early morning MCS in Iowa has prevented instability from rising to levels necessary for widespread storms this afternoon and evening, but still expecting scattered activity, especially in southeastern Wisconsin outside of the morning subsidence zone. The main hazard is expected to be lightning, but an isolated storm may become strong to severe with gusty to damaging winds and small hail. Storms will weaken around sunset, with the front stalling out near the Wisconsin/Illinois border between 9 and 11 PM CDT. Showers will increase in coverage as the front stalls (60-80%), with isolated embedded thunderstorms. This activity will generally remain along and south of the I-94 corridor, with some CAMs still indicating that the front will stall south of the WI/IL border and produce only scattered light showers. Regardless, rain will taper off by Sunday morning.

Drying and clearing conditions expected Sunday, with gusty northwest winds bringing in cooler temperatures in the upper 60s to low 70s. Overnight, expect light westerly winds and lows in the low 50s.

MH

LONG TERM

Issued 244 PM CDT Sat Jun 13 2026

Monday through Saturday:

Dry conditions are expected to persist through Monday under a weak ridge of high pressure, while a shortwave propagates through the northern Plains. This shortwave will turn winds to southwesterly and bring in thunderstorm chances by Tuesday. Morning convection may prevent destabilization and therefore strong to severe chances, but southern Wisconsin looks to be firmly within the warm sector so cannot rule it out at this point. The cold front from this system pushes through Tuesday night, bringing widespread storm potential (70-85%).

Cold front looks to stall south of the Wisconsin border Tuesday night, phasing with an incoming shortwave's warm front and deepening the incoming wave. Models indicate that this system will deepen a surface low rapidly, bringing additional widespread rain to southern Wisconsin on Wednesday into Wednesday night. The exact placement of this system is still dependent on the Tuesday activity, but it is certainly a timeframe to keep an eye on as we enter the work week.

Active weather pattern looks to continue through the end of the week, with multiple shortwaves progressing southeastward through the Upper Midwest. Best chances for additional storms arrive Friday into Saturday, which are currently output on the NBM as 20-30%. However, these PoPs are based on timing differences and confidence is high in periods of thunderstorms within the timeframe given.

MH

AVIATION

Issued 740 PM CDT Sat Jun 13 2026

VFR conditions tnt-Sun nt but scattered showers are forecast tnt along with slight chances for thunderstorms. Any precipitation that does form will likely have high cloud bases. Bkn040 stratocumulus to then develop for late Sun AM and last for much of the afternoon.

Gehring

MARINE

Issued 244 PM CDT Sat Jun 13 2026

Low pressure around 29.3 inches lingers in the Hudson Bay, allowing for continued gusty southwest winds through this evening. A Small Craft Advisory is in effect for southern Wisconsin nearshore waters for these gusty winds. This evening into tonight, a cold front from this system will shift winds to northwesterly and bringing isolated thunderstorms. Northwest winds continue through Sunday, becoming light and variable Sunday night as high pressure around 30.1 inches builds in the central Plains to Middle Mississippi Valley. Winds then shift southwesterly on Monday as high pressure slides southward and low pressure of 29.7 inches progresses southeastward through the northern Plains. Low pressure crosses Lake Michigan on Tuesday, with strong southwesterly winds to the south of the low. Thunderstorms are possible once again. Wednesday, an additional low pressure system will progress eastward into the Upper Midwest, bringing gusty southeasterly winds and perhaps some gales to the southern third. This low is also expected to cross Lake Michigan, bringing thunderstorms and gusty northwest winds by the overnight hours.

MH

MKX WATCHES/WARNINGS/ADVISORIES

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