textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Special Weather Statement in effect for elevated fire weather concerns today given warm and dry conditions with breezy winds.

- Chances for showers and thunderstorms (30 to 50 percent chances) remain for Monday afternoon and evening, as a cold front moves through the area. Gusty winds could occur with stronger storms.

- Warmer and breezy Monday, then cooler the rest of the week.

- Frost may occur toward the middle to later portions of the week.

UPDATE

Issued 515 AM CDT Mon May 4 2026

The primary update for today is the issuance of a special weather statement regarding the elevated fire weather conditions expected today. Refer to the fire weather tab for more information.

Otherwise latest trends in the short term models has been suggestive of a much drier low level environment that may play a role in significantly inhibiting potential convection later today. While showers and a few storms should still be expected it is a trend worth monitoring that may lead to less convection overall today. At the same time the drier low levels may cause storms to bring stronger gusts.

Kuroski

SHORT TERM

Issued 1206 AM CDT Mon May 4 2026

Tonight through Monday Night:

Outside of scattered high clouds overnight, expect mostly clear skies to continue into Monday morning. Light winds tonight will increase by daybreak, becoming breezy out of the southwest mid/late morning it the afternoon. Gusts of 25 to 35 mph are likely as a cold front approaches. It still looks like there is a potential for scattered showers and a few thunderstorms as the front moves through mid-afternoon into the evening. Kept precip chances capped at 50 percent though given the concern of dry air in the lower levels. A few models such as the GFS and NAM had much too high dewpoints this last afternoon into the evening compared to observations, and these models push the dewpoints into the mid 50s tomorrow and are thus higher with the precip chances. The RAP/HRRR dewpoints were closer to reality over the last several hours and are also lower tomorrow, with lower precip chances as a result. Though there will be some increased moisture ahead of the front, leaned the forecast towards the drier solutions. Still think a few storms could produce some gustier winds given the drier low levels.

Think the lower dewpoints and deeper mixing will result in temps a bit milder than previously expected, with highs likely approaching 80 across south and east portions of the forecast area.

There is still the potential for some post frontal showers tomorrow evening into tomorrow night, given some lingering frontogenesis aloft. Confidence isn't high in this second round of rain, so kept precip chances in the 20-30 percent range.

DDV

LONG TERM

Issued 1206 AM CDT Mon May 4 2026

Tuesday through Sunday:

Dry weather is expected Tuesday through Wednesday night under high pressure. Could see some frost Tue night and Wed night given the cooler/drier airmass in place and a decent radiational cooling potential both nights.

A more active shortwave pattern is expected later in the week and into the weekend, bringing shower chances to southern Wisconsin Thursday, Friday, and again on Sunday. Temps are expected to warm back to around normal by the end of the week.

DDV

AVIATION

Issued 515 AM CDT Mon May 4 2026

Southwest winds will become breezy mid/late morning through the afternoon, with gusts of 25 to 30 knots likely ahead of a cold front. Scattered showers and a few thunderstorm will then be possible along and ahead of the cold front mid-afternoon into the evening. A few of the storms could produce some gustier winds. Ceilings will likely remain VFR with the showers/storms given a fair amount of dry air in the lower levels. Light rain chances will linger into at least the evening due to the potential for some post frontal showers. Winds will be lighter and out of the northeast behind the cold front Monday evening.

Kuroski

MARINE

Issued 1206 AM CDT Mon May 4 2026

Southwest winds will increase Monday morning ahead of a cold front in association with low pressure of 29.0 inches moving across Ontario. A short 6 hour period of Gales is anticipated over the northern third of Lake Michigan between 10am and 4pm CDT. Small Craft Advisory conditions are expected for the nearshore waters tomorrow. Winds then ease through the afternoon from north to south over the lake as the cold front moves south. Winds behind the front will become northwesterly.

The pressure gradient will then ease over the lake Tuesday through Thursday, with light and persistent west to northwest winds occuring. Light and variable winds may briefly occur at times as various weak surface ridges move across the lake.

DDV

FIRE WEATHER

Issued 140 AM CDT Mon May 4 2026

Warm, dry and breezy conditions today will lead to an elevated concern for fire weather across southern WI. Given recent rains and green up largely being complete, it is not thought that fuels are at a near critical level but the weather conditions are. Highs in the upper 70s, relative humidities falling to the 20-30 percent range and sustained winds around 15-20 mph with gusts to 35 mph all contribute to the increased fire weather concerns. The showers and storms potential later today may raise dewpoints in those areas but those chances remain uncertain and at best scattered and thus the risk will persist for all of southern WI.

Kuroski

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...Gale Warning...LMZ261-LMZ362-LMZ364-LMZ563...10 AM Monday to 4 PM Monday.

Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...10 AM Monday to 7 PM Monday.