textproduct: Milwaukee/Sullivan

KEY MESSAGES

- High pressure moves in today with temperatures around normal.

- Chances (mainly 20 to 30 percent) for precipitation returns to the area for Thursday. Potential for a few thunderstorms as well.

UPDATE

Issued 605 PM CDT Mon Mar 23 2026

No major changes to the going forecast this evening.

CMiller

SHORT TERM

Issued 100 PM CDT Mon Mar 23 2026

Tonight through Wednesday night:

Modest south to southeast winds tonight behind a lake breeze as the high pressure shifts east of CWA tonight into the mid Great Lakes region. A front will also be pushing into the region overnight with the best forcing and deep moisture off to the north but some WAA, perhaps some weak shortwave activity aloft with moisture between 500-700mb there will be some potential for precip to fight their way to the surface. However, dry air is largely expected to win out tonight as the surface to 800mb layer looks quite dry and with such a brief period of moisture aloft the period to see that layer moisten up is short thus making precip unlikely but I have included some chances for a few flurries overnight into early Tuesday morning.

Tuesday/Tuesday night looks largely quiet as high pressure largely wins out but winds remain southerly with developing low pressure out to the west. Moisture aloft will be present likely bringing a mostly cloudy day. Any precip Tuesday night into Wednesday will remain well north associated with the warm front from the low pressure system to the west. Into Wednesday some models bring some light chances for a shower across far eastern WI but the lack of moisture in most models suggests these chances are limited. If moisture in future models runs increases across various models Wednesday, there will be sufficient WAA to at least allow for some light showers/drizzle. By Wednesday night, expect drier conditions to return as the mid to upper levels largely dry out.

Kuroski

LONG TERM

Issued 100 PM CDT Mon Mar 23 2026

Thursday through Tuesday:

Synopsis: West-northwest upper level winds will persist across the western Great Lakes through the period, with a lack of pronounced mid-level waves leaving precipitation chances confined to surface frontal passages. The first of two cold fronts remains forecast to cross southern Wisconsin during the day on Thursday, bringing rain areawide with a few thunderstorms possible near the Wisconsin- Illinois border. Noticeably cooler conditions will prevail behind the departed front Friday into Saturday, with highs 5-10 degrees below normal on Friday afternoon. Temperatures will gradually rebound from the second half of the weekend through the start of next week. The next cold front will move into Northern Plains- western Great Lakes vicinity next Monday, though its arrival & affiliated precipitation chances will likely hold off until just beyond the end of the current long term period.

Thursday: The best precip chances of the current long term period arrive along a passing cold front. Very mild conditions in place ahead of the front---current guidance suggests the potential for highs 10-15+ degrees above normal---will be supportive for all rain during the frontal passage. Whether any convection can mix in with the rain will depend upon the precise timing of the cold frontal passage, with available guidance showing a range of morning or afternoon timings. A later/slower solution would allow more time for instability to work toward southern Wisconsin, introducing some potential for embedded thunderstorms. At present, said slower/later solution remains less favored amongst available guidance, so the forecast has been trended toward all rain & no thunder in the mid- day update. Will nevertheless be monitoring trends, particularly along & south of the I-94 & US-18 Corridors, where the best potential for thunderstorms would exist in the event of a slower cold frontal passage. A much drier air mass will quickly work into southern Wisconsin behind the cold front by Thursday evening, with the expectation that precipitation will shut off before any changeover to appreciable snowfall can materialize. Can nevertheless rule out a few wet snowflakes mixing in with rain as precip vacates during the late afternoon/early evening hours.

Thursday night through Saturday: A strong push of cold advection will lead to seasonably chilly conditions, particularly through Friday afternoon. Will see a blustery start to the day Friday, with wind chills forecast to fall into the teens by daybreak. Expect highs in the low-mid 40s away from Lake Michigan Friday afternoon, with readings remaining in the mid-upper 30s closer to Lake Michigan. Gradual improvements will occur during the day Saturday.

Quigley

AVIATION

Issued 606 PM CDT Mon Mar 23 2026

VFR conditions continue amid light and variable winds as high pressure passes overhead. Winds should become southerly by 06Z tonight and become breezy as warm advection increases over the region and the high moves east. There may be a band of warm advection driven precip that triggers aloft overnight, but model soundings show exceptionally dry low levels, so there is some doubt we'll see anything beyond isolated flurries as the warm advection moves through between 06 and 15Z Tuesday. Cloud cover is also expected to increase overnight and into Tuesday, but cigs should remain in the VFR category.

CMiller

MARINE

Issued 100 PM CDT Mon Mar 23 2026

Low pressure of 29.6 inches off the coast of Maine will continue east as high pressure of 30.5 inches in the Northern Plains pushes toward and builds into Michigan. The pressure gradient is gradually weakening between these two systems which will bring an end to the gusty winds over the next few hours as the high builds in. Light and variable winds are expected into this evening as the high moves overhead.

However, into the late overnight hours and into Tuesday winds in the north half of the lake may become breezy as a stalling front moves over the north side of the lake behind the departing high. This may actually bring south winds that may approach gales although gales remain unlikely at this time. This will however bring a brief window of chance Tuesday morning for small craft conditions over the northern tiers of the nearshore waters. Winds are currently expected to remain just below small craft thresholds. Winds will weaken through Tuesday as the front weakens and high pressure to the north squeezes out the stronger pressure gradient to the east.

Largely south winds remain through Wednesday, as a broad low pressure around 29.8 inches approaches from the west. Chances for precipitation on Tuesday and again on Wednesday though primarily for northern parts of the lake.

The next best chance for gales will come Thursday evening as the backside of a low pressure system around 29.6 inches works southeast.

Kuroski

MKX WATCHES/WARNINGS/ADVISORIES

WI...None. LM...None.