textproduct: Milwaukee/Sullivan

KEY MESSAGES

- Record high temperatures in the upper 60s possible on Monday. - Rain with some embedded thunderstorms expected Tuesday afternoon through Tuesday night (70-90%). Temperatures will drop into Wednesday, with a transition to wintry mix, then potential for light snow and rain (40-60%).

- Active pattern for the later half of the week with increased precipitation chances Thursday evening/night, and again Saturday night into Sunday.

SHORT TERM

Issued 1150 PM CDT Sun Mar 8 2026

Today (Monday) through Tonight (Monday night):

A southwest breeze continues as deep low pressure tracks eastward across Lake Superior, with strong low-level WAA holding low temperatures to the 40s early this morning. Forecast soundings hint at only a few mid to high altitude clouds (over the 700mb level, mainly further north towards central WI) through the daytime hours today, leaving skies almost completely clear. Light southwesterly WAA continues through the morning, then winds decelerate (becoming light and variable) through the afternoon as a weak frontal boundary sags southward into the region. Forecast highs are in the mid to upper 60s across the region. Both the Milwaukee and Madison high temperature records for March 9th (67 in 2016 and 66 in 1977 respectively) could possibly be tied or broken. The southwesterly flow will block any attempt at a lake breeze before noon, though one may develop later in the afternoon as the frontal boundary sags south, particularly further north

A light northeasterly breeze gradually develops Monday night as high pressure builds into central Canada and low pressure deepens from the central Plains to the Mississippi River valley. The cooling effect of Lake Michigan and mostly clear skies will work together to rapidly drop temperatures Monday night, with a low in the mid to upper 30s for much of the region (low 40s towards the IL border).

Sheppard

LONG TERM

Issued 1150 PM CDT Sun Mar 8 2026

Tuesday through Sunday:

Low pressure is expected to track east-northeastward from the central Plains through Ohio mid week, resulting in 60-90% precip chances on it's closest approach Tuesday into Wednesday. Though the center of the low is currently expected to pass just south of the region, and northeasterly winds off Lake Michigan will halt the advance of the surface warm front well shy of our region, some elevated convection (thunderstorms) north of the warm front will be possible in southern WI, especially further south towards the IL Border where a marginal (level 1 out of 5) risk for severe hail is present. This activity would likely arrive (roughly) late Tuesday afternoon, peak in the evening, then transition to light stratiform precip late Tuesday night. Forecast soundings reveal an LFC above the 700mb layer, with plenty of stable marine air beneath it. We'll be watching the track of the low closely, but for the time being we're mainly looking at small (less than 1 inch) hail potential and lightning.

Light stratiform precip is likely to continue late Tuesday night through Wednesday morning (65-90% chance), with ~45% chances to continue into Wednesday afternoon. A northwest to southeast transition from rain to light wintry mix or snow is looking likely early in said period, with a chance for slushy accumulations and slowdowns on the Wednesday AM commute (particularly for the northern half of the CWA, north of the I-94 corridor). It's too early to advertise snow totals with this type of mixed precip event (especially with the antecedent warm weather and soil / pavement surface temps), but our best guess is in the ballpark of 1 inch slushy snow accumulations north of the I-94 corridor, with only a fraction of an inch to zero accumulation further south due to melting / later arrival of the cooler temps and rain to snow transition.

Predominantly dry weather expected Wednesday night into Thursday as high pressure builds in behind the departed low. A clipper system is then expected to track eastward into our region, delivering ~60% precip chances Thursday evening / night. Both rain and wintry precip are possible with this system, though the ensemble mean system track is centered further north in the state, hence we're leaning towards mostly rain and little / no wintry accumulation despite the nocturnal timing. Additional chances for FGEN or clipper system driven precip at times this upcoming weekend. Ensemble temperature IQRs are centered near seasonal norms this weekend, and may trend colder into the first half of next week.

Sheppard

AVIATION

Issued 1150 PM CDT Sun Mar 8 2026

VFR conditions prevail overnight through Monday. Dry weather and mostly clear skies, with a few periods of broken upper-altitude cloud cover (mainly further north). A southwest breeze continues overnight, with the 2,000 ft AGL winds (around 50 kt) outpacing the surface flow. As such, LLWS has been added to all TAFs through just after daybreak Monday morning.

A light southwest breeze lingers into post-dawn Monday morning / early Monday afternoon, gradually transitioning to light and variable as a weak frontal boundary sags southward into the region. From late Monday night into early Tuesday morning, a northeasterly breeze developing north of the frontal boundary might lead to the development of low cloud ceilings or fog, though there remains plenty of uncertainty in model guidance.

Sheppard

MARINE

Issued 1150 PM CDT Sun Mar 8 2026

Winds will remain gusty and southwesterly overnight into Monday as low pressure of 29.1 inches progresses eastward across Lake Superior. A few gales are possible Monday morning (particularly over the northern third of Lake Michigan) as low pressure makes its closest approach. High pressure then builds in briefly Monday afternoon, allowing for lighter and variable winds, before a cold front brings gusty northeasterly winds Monday night into Tuesday.

Low pressure around 29.6 inches then develops in the central Plains and progresses northeastward into northern Illinois Tuesday night, keeping winds northeasterly and gusty, with some potential for isolated thunderstorms across the southern third of the Lake. Low pressure ejects northeastward into Wednesday morning, turning winds northwesterly. North to northwest gales are possible Wednesday morning through Wednesday afternoon. Winds gradually diminish into Thursday morning.

Sheppard

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 7 AM Monday.