textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Another round of showers (60-90+ percent) is forecast tonight.

- An active weather pattern returns late this weekend into next week. Warm and humid conditions and more showers and storms are expected.

UPDATE

Issued 527 AM CDT Thu Apr 9 2026

Clear skies are expected across southern WI for most of the day. Expect westerly winds up to 15 kt this afternoon. A lake breeze may develop in southeast WI but not make it very far inland. Temperatures will be cooler than yesterday, but still above normal, especially in southeast WI with highs in the lower/mid 60s.

Widespread rain (light to moderate) will quickly spread into southern WI from the southwest this evening and then end from west to east through 7 AM Friday. The NBM in the previous forecast had higher rainfall amounts than the 00Z DESI Grand Ensemble so I trended the forecast totals downward. Highest amounts of up to a half inch (58% chance of greater than 0.5 inch) will be southeast of a Janesville to Milwaukee line. There is high confidence (50-70%) of less than a half inch north of a line from Mineral Point to Beaver Dam to southern Sheboygan County. The chance for a few rumbles of thunder in the moist adiabatic profile tonight is also trending southward, south of the IL border.

Cronce

SHORT TERM

Issued 1150 PM CDT Wed Apr 8 2026

Today through Saturday:

Two distinct sw-ne bands of showers are prevalent over srn WI. The initial band over far se WI is associated with warm, moist advection in the low to mid level thermal ridge. The second band from sw WI to the Fond du Lac area is associated with sfc-850 mb frontogenesis. The cold front and rainfall will move esewd through the early morning ending at MSN around 07Z and MKE around 10Z.

Weak sfc ridging and a wly sfc flow can be expected for Thu with cooler temps than Wed, but still on the mild side. A wave of low pressure supported by a weak shortwave trough will then track from the central Great Plains into far srn lower MI Thu nt. PWATs of 0.75-1.00 inches will shift back north into the region. Well organized 850-700 mb frontogenesis and the nose of a low level jet near the IL border will support widespread showers and a few rumbles of thunder during this time. 0.50-0.90 inches of rain are forecast along and south of a line from Mineral Point to Madison to Port Washington.

High pressure will then track from ern SD to the Upper MS River Valley on Fri, then across srn WI Fri nt. The high will then reach the Mid Atlantic States around 00Z Sun. Pleasant wx will prevail with high temps Fri-Sat in the middle to upper 50s well inland, with upper 40s at the Lake MI shoreline. The onset of low to mid level warm, moist advection will bring 20-30 percent chances for showers Sat afternoon over south central WI.

Gehring

LONG TERM

Issued 1150 PM CDT Wed Apr 8 2026

Saturday night through Wednesday:

This period will see a pattern change to swly flow aloft with low pressure areas developing over the high plains and tracking to the north or over srn WI. Relatively warm and humid air will arrive for Sun-Tue with repeated rounds of showers and storms from Sat nt-Tue. Showers may linger into Wed along with somewhat cooler temps. Will be monitoring rivers for a possible return of some flooding to some degree.

Gehring

AVIATION

Issued 527 AM CDT Thu Apr 9 2026

Clear skies are expected across southern WI for most of the day. Expect westerly winds up to 15 kt this afternoon. A lake breeze may develop in southeast WI but not make it very far inland, so did not include it in the MKE TAF but there is uncertainty.

Widespread rain (light to moderate) will quickly spread into southern WI from the southwest this evening and then end from west to east through 12Z/7AM. IFR ceilings are expected in southeast WI after midnight but will return to VFR by mid-late morning.

Cronce

MARINE

Issued 527 AM CDT Thu Apr 9 2026

Low pressure around 29.7 inches over far western Ontario will track north of Lake Superior through late morning. The winds behind the associated front dropping down Lake Michigan early this morning will be westerly and light. The Gale Warning will be allowed to expire at 4 AM.

Light and variable winds will prevail this afternoon through Saturday morning, until breezy southerly winds return later in the weekend. Southerly gales are possible over the north half Sunday into Monday morning.

Cronce

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...None