textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Frost Advisory remains in effect until 8 AM CDT this morning for most of southern Wisconsin.

- A clipper system brings higher-end shower chances (60 to 90 percent) for Tuesday morning. A passing cold front Tuesday afternoon may bring a few thunderstorms. Gusty winds and small hail may occur with the strongest storms, if they develop.

UPDATE

Issued 432 AM CDT Mon May 11 2026

The Frost Advisory remains in effect until 8 AM CDT this morning for most of southern Wisconsin. Frost is expected in these areas, as lows drop into the lower to middle 30s. Patchy frost may occur in far southeast Wisconsin as well.

High pressure will bring quiet weather today. Northeast to east winds will keep cooler temperatures in the 40s to middle 50s in eastern portions of the area, with lower 60s well inland.

Warm air advection then develops tonight into Tuesday morning, with a warm front pushing north into and through the area Tuesday morning. This should bring a period of showers (60 to 90 percent) to the area Tuesday morning. Warm and breezy conditions should develop on Tuesday.

A cold front should then move through the area Tuesday afternoon. CAMs are suggesting scattered showers and a few thunderstorms (20 to 40 percent chances) may develop along the front. Forecast soundings are showing tall skinny mean layer CAPE of 300 to 700 J/kg in the afternoon with strong deep layer bulk shear of 45 to 55 knots. NAM/GFS forecast soundings seem overdone with dew points so adjusted for this to get lower mean layer CAPE values. If storms can develop, gusty winds and small hail may occur in the strongest storms.

Dry conditions return Tuesday night with gusty northwest winds and cooler air moving back into the area.

Wood

SHORT TERM

Issued 1158 PM CDT Sun May 10 2026

Today through Tuesday night:

Overnight temperatures have trended slightly warmer, but a frost advisory will still remain for all of southern WI save for MKE, Racine, and Kenosha Counties.

High pressure will move overhead today, continuing to promote dry conditions. The weak pressure gradient will promote a lake breeze during the late morning and into the afternoon, which will push east to southeast winds from the lake inland with time. As a result, highs in the 50s are expected for counties close to Lake Michigan, while highs in the low 60s are expected far inland.

The high pressure will then quickly shuffle east Monday night as a low pressure moves from the northern plains to the Arrowhead region of MN by dawn on Tuesday. The low will drag a warm front over Wisconsin and widespread showers are expected Tuesday morning. MUCAPE will be non-existent, so no thunder is expected with the morning round. Showery precip may continue into the afternoon as the warm sector of the low pressure system moves overhead, with the low pressure center moving into northern WI during the late morning into the afternoon. Models then suggest there may be some redevelopment along the cold front over southeast Wisconsin late Tuesday afternoon. Airmass recovery doesn't look overly conducive to building large CAPE and only skinny CAPE supporting between 500 and 1000 J/kg of SBCAPE will result along the front. Effective shear of 30 knots will be enough for storm organization though, and any stronger storms that sustain themselves may feature small hail and gusty winds. The SPC has us in a marginal risk on Tuesday, with the severe weather threat looking isolated at best.

CMiller

LONG TERM

Issued 1206 AM CDT Mon May 11 2026

Wednesday through Monday:

Temperatures dip on Wednesday in the post-frontal CAA regime with highs in the upper 50s to low 60s. High pressure moves in and lingers on Thursday with temperatures rebounding to near 70.

A more active pattern then sets up Friday into early next week. Multiple waves of warm advection look possible, with on and off shower and storm chances. The NBM maintains 25 to 45% PoPs Friday through Monday given the nebulous rain chances.

CMiller

AVIATION

Issued 432 AM CDT Mon May 11 2026

High pressure will bring quiet weather today. Northeast to east winds are expected for terminals closer to Lake Michigan, with light and variable winds well inland. Scattered diurnal cumulus clouds may develop around 5000 feet AGL this afternoon. Modest southeast winds are expected tonight.

A warm front is expected to push north into and through the area Tuesday morning. This should bring a period of showers (60 to 90 percent) to the area Tuesday morning. Breezy south to southwest winds should develop on Tuesday. Ceilings and visibility should remain VFR category during this period.

A cold front should then move through the area Tuesday afternoon, with scattered showers and a few storms possible (20 to 40 percent chances). If storms can develop, gusty winds and small hail may occur in the strongest storms. Dry conditions return Tuesday night with gusty northwest winds.

Wood

MARINE

Issued 432 AM CDT Mon May 11 2026

High pressure around 30.4 inches is expected to move from southern Manitoba to over Lake Michigan today. Light to modest north to northeast winds today should become southeast to south tonight.

Low pressure around 29.7 inches should then move gradually east southeast across the region Tuesday into Tuesday night. The low will bring a cold front southeast through the region. Gusty south to southeast winds are expected ahead of the front Tuesday, with a few gales possible during a brief period Tuesday afternoon over the open waters. Winds then veer west to northwest behind it and remain gusty for Tuesday night into Wednesday.

A Small Craft Advisory will likely be needed Tuesday into Tuesday evening and possibly again on Wednesday for the nearshore waters of Lake Michigan. Winds and waves may reach Small Craft Advisory levels during these periods.

High pressure around 30.3 inches should move southeast into the region Wednesday night into Thursday, bringing lighter winds. Gusty south winds may then develop Friday.

CMiller/Wood

MKX WATCHES/WARNINGS/ADVISORIES

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

LM...None.