textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Dry weather under high pressure expected through the weekend and into next week. Fire weather concerns may increase into early next week.

- There is a high swim risk today for Ozaukee, Milwaukee, Racine and Kenosha County lakeshore areas due to persistent and elevated onshore winds.

SHORT TERM

Issued 1200 PM CDT Sat May 30 2026

Today through Sunday night:

High pressure is sinking south down from James Bay this afternoon into tonight and will settle across the Great Lakes Region this weekend. As high pressure moves in, the breezy northeast winds will weaken across the state. This weakening trend in the winds has already begun for parts of southern Wisconsin as gusts are currently sporadic. With the winds already weakening late this morning/early this afternoon, the building waves that were expected across the nearshore waters have under performed a bit. While certainly still windy and wavey, the high swim risk may end a bit earlier in the evening if winds decrease further.

Light and variable winds will set up across southern Wisconsin Sunday as the center of the high pressure settles over Michigan. Temperatures are expected to be warmer with highs in the mid 60s to upper 70s (cooler near Lake Michigan and warmer inland). Under the light winds, a lake breeze is expected to develop and move inland during the afternoon/evening hours Sunday which will cool temperatures off as it races inland. Mostly clear to partly cloudy skies are expected.

Patterson

LONG TERM

Issued 1200 PM CDT Sat May 30 2026

Monday through Saturday:

Surface high pressure will retreat to the southeast heading into Monday morning. Meanwhile, a shortwave trough will move through the 500 mb flow aloft, wrapping around the trough in the northern Plains Monday. As this shortwave moves north across IA, MN, and the Dakotas, some upper level PVA looks to advance northeast across Wisconsin. Meanwhile a weak backdoor cold front is expected to move down from Canada. With high pressure lingering across the Great Lakes Region, there will be a lack of moisture to pull from with this transient lift. However, there are low chance POPs 10-20% in far southwestern Wisconsin Monday. Any showers that does manage to reach southern Wisconsin should dissipate quickly as it enters into a drier more stable air mass.

Otherwise, high pressure will return shortly by Monday afternoon/evening as a Hudson Bay high descends down to Wisconsin. This area of high pressure will linger in the Great Lakes Region through midweek before advecting southeast toward the Mid Atlantic. The low fire weather concerns remain through this period.

Looking further ahead toward the end of the week (Thursday & Friday), guidance has the 500 mb pattern we have been stuck in breaking down. With the ridge aloft diminishing and moving east, an area of low pressure in the Plains should finally start to advance eastward toward the Great Lakes. Timing and strength of the low vary among guidance, but this looks to be the first decent chance for Rain. Patterson

AVIATION

Issued 1200 PM CDT Sat May 30 2026

VFR conditions are expected through the period. Breezy northeast to east winds will continue across southern Wisconsin through this evening (gusts to 20 kts possible) before weakening and turning to southeasterly. Light southeast winds will continue through Sunday becoming light and variable Sunday night. Patchy high clouds will stream in from the west across south central Wisconsin, while eastern Wisconsin stays mostly clear through the period.

Patterson

MARINE

Issued 1200 PM CDT Sat May 30 2026

High pressure around 30.2 inches centered over northern Ontario will move south today and become centered over Michigan tonight into Sunday. This area of high pressure will linger across the Great Lakes Region into Wednesday. Northeast to east winds will remain breezy behind a backdoor cold front today, weakening tonight and becoming southeasterly. Weak southeast winds will become light and variable Sunday night ahead of another backdoor cold front for Monday. Northeast winds will become breezy Monday evening into Monday night.

The high pressure over the Great Lakes will begin to exit southeast toward the Mid Atlantic coast late Wednesday into Thursday as low pressure around 30.0 inches develops in the Plains. Winds will turn to the south to southwesterly and increase Thursday.

Breezy northeast winds today behind the backdoor cold front has caused waves to build in the nearshore zones across Wisconsin. Small Craft Advisory conditions are expected to persist until the onshore winds weaken later this evening into tonight.

Patterson

MKX WATCHES/WARNINGS/ADVISORIES

WI...Beach Hazards Statement...WIZ060-WIZ066-WIZ071-WIZ072 until 9 PM Saturday.

LM...Small Craft Advisory...LMZ644-LMZ645-LMZ646 until 9 PM Saturday.