textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Dry and cool conditions are expected through Wednesday night. Lows in the lower to middle 30s are expected overnight and Wednesday night, bringing widespread frost. A Frost Advisory is in effect overnight through early Wednesday morning for most areas except along the Lake Michigan shore.

- Scattered showers (20 to 30 percent chances) and a rumble of thunder may occur Thursday and Friday with peak daytime heating. A brief snow shower may mix in Thursday morning with cold temperatures aloft.

- Temperatures are expected to gradually warm up later this week through the weekend.

UPDATE

Issued 450 AM CDT Wed May 6 2026

No major update to the forecast today with largely dry and cool conditions. Frost this morning and likely again tonight but otherwise expect quiet weather overall.

Kuroski

SHORT TERM

Issued 1155 PM CDT Tue May 5 2026

Overnight through Friday night:

Scattered to broken middle to high clouds will continue to push east northeast across the area overnight, gradually becoming scattered into Wednesday morning. Light and variable winds are expected overnight into early Wednesday morning.

Lows overnight should drop into the lower to middle 30s in most areas away from the lake. The Frost Advisory continues for all of southern Wisconsin overnight into early Wednesday morning.

Broken diurnal stratocumulus clouds should then develop from middle to late morning Wednesday and linger through the afternoon. There should be west northwest winds developing again by midday lingering into the afternoon, with some gustiness at times. There may also be a southeast lake breeze that develops in the afternoon for areas near Lake Michigan. Highs should reach the middle 50s for most areas, with temperatures turning cooler near the lake in the afternoon.

Another night of frost should occur Wednesday night into early Thursday morning, with light winds, skies clearing out and radiational cooling. Lows should drop into the middle 30s for most areas except near Lake Michigan, with some lower 30s in spots. Another round of Frost Advisory headlines will eventually be needed for this period.

Cyclonic flow at 500 mb should allow for some differential CVA to push through the area Thursday into Thursday night, with some weak warm air advection trying to focus over or to the south of the area. Forecast soundings are showing some moisture and weak instability developing with steep low level lapse rates Thursday afternoon and evening. Kept small chances (around 20 to 30 percent) for showers in the forecast. There may be a rumble or two of thunder, as the mean layer CAPE extends above the -10 degree Celsius level. Highs should rise into the upper 50s to lower 60s Thursday, perhaps cooler near the lake if a lake breeze develops.

Another round of differential CVA from passing 500 mb vorticity maxima pushes through Friday into early Friday evening, with perhaps another push of low level warm air advection. Forecast soundings show a similar setup with some moisture and weak instability with peak heating. Kept small chances (20 to 30 percent) for showers Friday into Friday evening. Highs may rise into the middle 60s inland, with cooler temperatures near Lake Michigan.

Wood

LONG TERM

Issued 1155 PM CDT Tue May 5 2026

Saturday through Tuesday:

500 mb cluster analysis continues to show an elongated and anomalously deep trough over Ontario Saturday, which shifts southeast and becomes less deep early next week. This should keep the area within northwest flow at 500 mb during this time. Ensemble means are generally showing some warm air advection developing Saturday, with a cold front pushing southeast through the area Saturday night.

This should bring warmer temperatures Saturday, along with better chances (30 to 50 percent) for showers and perhaps a few storms Saturday into Saturday night. The highest chances would be in southern portions of the area, where the front will be with peak heating.

Ensemble means generally bring high pressure through the region Sunday into Monday, bringing dry conditions and temperatures closer to seasonal normal values. Low pressure developing in Minnesota Tuesday may have some warm air advection develop ahead of it into the area, which may bring the next chances (20 to 30 percent) for showers and a few storms.

Wood

AVIATION

Issued 500 AM CDT Wed May 6 2026

VFR conditions are expected across southern WI through the TAF period with high CIGS today and modest northwest winds. Thursday will be a bit cloudier but will remain around 5kft with a chance for showers and even a weak storm. Modest west winds expected Thursday.

Kuroski

MARINE

Issued 1155 PM CDT Tue May 5 2026

High pressure around 30.0 inches will continue to slide southward into the central Plains into Wednesday, bringing light and variable winds to Lake Michigan. South winds should then develop Thursday, with south to southwest winds continuing through Saturday, as high pressure around 30.0 inches remains across the central Plains. Low pressure around 29.5 inches should move southeast across portions of the region Saturday into Saturday night. A passing cold front with the low will turn winds northwesterly Saturday night into Sunday. High pressure around 30.2 inches should then build into the western Great Lakes region later Sunday into Monday.

Wood

MKX WATCHES/WARNINGS/ADVISORIES

WI...Frost Advisory...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057- WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066- WIZ067-WIZ068-WIZ069-WIZ070-WIZ071-WIZ072 until 8 AM Wednesday.

LM...None.