textproduct: Milwaukee/Sullivan

KEY MESSAGES

- A Beach Hazard Statement is in effect from this afternoon through early Thursday afternoon for a High Swim Risk at beaches in Milwaukee, Racine, and Kenosha Counties.

- Expect a gradual warming trend through the Memorial Day weekend.

- Rain chances return Friday afternoon and night (40-70%), with lower chances through the holiday weekend.

UPDATE

Issued 524 PM CDT Wed May 20 2026

Mid and high level clouds will increase from west to east this evening into tonight, especially across the northern half of the forecast area. Otherwise, quiet weather is expected and the forecast looks on track for the evening and overnight hours.

DDV

SHORT TERM

Issued 126 PM CDT Wed May 20 2026

This afternoon through Thursday:

Diurnal cumulus clouds developed quickly this morning. The wind direction became northeast to east quicker than previously forecast (much earlier than any models suggested) due to the cold lake accelerating the lake breeze.

Expect the clouds to gradually lift and thin out this afternoon as drier air mixes in. Clearing near the lake is also expected with the lake breeze pushing inland.

The surface high pressure will slide into the Upper Great Lakes this afternoon and then sit over us through Thursday night. Meanwhile, a mid level shortwave that is currently over Nebraska will track through southern WI tonight through Thu afternoon. Look for mid level clouds to spread into southern WI overnight. Cannot rule out a few sprinkles during the day Thursday during the time of the more robust portion of the shortwave, but dry air will dominate below 10kft.

Easterly winds will continue this period, although the lakeshore winds are expected to shift more northeast Thursday afternoon after the passage of that shortwave. The persistent onshore winds will allow for high waves to build along the lakeshore. The Beach Hazards Statement for Milwaukee, Racine and Kenosha counties start time was moved up to 3 PM this afternoon and extended in time to Thursday at 1 PM.

Cronce

LONG TERM

Issued 126 PM CDT Wed May 20 2026

Friday through Wednesday:

A broad low pressure trough setting up over the Plains and the gradually departing Great Lakes high will allow for an increasing pressure gradient over southern WI Friday. The steady/higher onshore winds will create an uptick in the waves once again, so another Beach Hazards Statement for a high swim risk will be needed early Friday morning through Saturday morning.

That broad upper trough will develop into two distinct surface lows on Friday; one over SD/NE and one over IL/IN. Models have been a little indecisive about these surface lows (due to the uncertain nature of upper lows), but it is important to note that the precip chances for southern WI Friday afternoon/night will depend on the strength/track of the IL/IN low. We have fairly high chances in the forecast right now (60-80%, highest east). There is some concern that dry air in the low levels could inhibit the more widespread precip from reaching the ground.

That upper trough will push into northern WI by mid-late Saturday morning which will end our precip chance. However, there may be some lingering precip from an additional upper trough that could track into southern WI during the day Sat, but this would be light and short-lived.

Our forecast is currently mostly dry for Sunday & Monday, but there are enough ripples in the upper level flow that there could be a few light showers possible. The bottom line is that Memorial Day weekend will not have any complete wash-outs for those with outdoor plans, and there will be a warming trend to the temperatures (reaching 80s by Monday for inland areas). However, expect a lake breeze each afternoon.

Beyond Monday, it looks like southern WI could be getting into a wetter pattern, but there are some indications that the moisture would only return to MN and IA and not as far east as WI/IL. Stay tuned. Temperatures look above normal.

Cronce

AVIATION

Issued 524 PM CDT Wed May 20 2026

Mid and high level cloud will gradually increase this evening into tonight, with mostly cloudy skies expected Thursday as an area of warm air advection aloft moves through. Despite the forcing from the warm air advection, dry weather is expected tomorrow due to very dry conditions in the lowest 8-10 kft. Not out of the question for a few sprinkles, but most locations will likely remain dry. Northeast winds 5-10 knots through tonight will become more easterly on Thursday, except for near Lake Michigan where winds may remain from the northeast.

DDV

MARINE

Issued 126 PM CDT Wed May 20 2026

Winds will becoming northeasterly for the whole lake by this afternoon as high pressure builds into the Upper Great Lakes region and then lingers into Thursday.

Gusty northeast winds will persist through midweek, especially over the southern half of the lake, and with building waves along the western lakeshore. High pressure continues to build to as it lifts northeastward across Ontario and Quebec Friday through the weekend with easterly winds continuing across Lake Michigan. Expecting winds to increase during this timeframe due to a broad low pressure trough setting up over the Plains.

A Small Craft Advisory is in effect south of the North Point Light from this afternoon through early Thursday afternoon due to high waves from persistent easterly winds. There should be a 6-8 hour lull in the 3-5ft waves Thursday afternoon/evening before higher winds and therefore higher waves return Thu nt-Fri nt. We will probably just issued one long S.C.Advy to account for this.

Cronce

MKX WATCHES/WARNINGS/ADVISORIES

WI...Beach Hazards Statement...WIZ066-WIZ071-WIZ072 until 1 PM Thursday.

LM...Small Craft Advisory...LMZ644...10 PM Thursday to 10 PM Friday.

Small Craft Advisory...LMZ645-LMZ646 until 10 PM Friday.