textproduct: La Crosse

KEY MESSAGES

- Outside of low, light precipitation chances grazing northwestern peripheral counties in southeast Minnesota and central Wisconsin, a mostly dry Sunday is expected before precipitation chances increase Sunday night through Monday morning.

- Strong to severe storm chances remain for Monday afternoon and evening primarily for the southern half of the forecast area from northeast Iowa into southwest Wisconsin. Local forecast area on northern periphery of higher confidence for stronger storms. All hazards (i.e., large hail, damaging winds, tornado) remain possible where severe storms form.

- Colder, slightly below normal temperatures expected through next week.

DISCUSSION

Issued at 1231 PM CDT Sat Apr 25 2026

Today & Sunday:

Ongoing light precipitation grazing local northwestern peripheral counties from southeast Minnesota through central Wisconsin has had little to no local impacts outside of a sharp temperature gradient resultant of diurnal heating influences raising temperatures in the mid 60s from northeast Iowa through west- central Wisconsin. Expect these light precipitation chances to linger along the accompanying pressure saddle shrink/stretching axis over these same areas into tonight. Eventual enhancement in synoptic forcing from a subtropical jet streak seen nearing the eastern Pacific on GOES upper level derived winds advects the higher moisture northeast through the Upper Midwest through the end of the weekend.

Sunday Night & Monday Morning Precipitation Chances:

Resultant increasing precipitation chances progress from west to east through the local forecast area Sunday evening, becoming widespread by Monday morning. Although, ongoing storms will be outrunning increased instability within the warm sector as isentropic upglide progresses northeast through the forecast area. Therefore, while widespread, stronger storm chances initially remain lower locally, they can't be completely ruled out as ongoing storms attempt to penetrate northeast while a tightening pressure gradient associated with upstream cyclogenesis affects the local forecast area. While enhancement of a potential low level jet will ultimately depend on location of cyclogenesis upstream of the forecast area, the additional forcing along its terminus will encourage storm development, currently expected along our western periphery.

Strong to Severe Storm Chances Monday Afternoon & Evening:

Similarly, northern extent of unstable airmass spreading northeast through Monday remains dependent on location of cyclogenesis upstream subsequently traversing/grazing the local forecast area. Synoptic ascent from phasing of the mid level wave due to strengthening of the subtropical jet streak along its base as well as upstream of its axis will provide required forcing for storm chances to reach the forecast area through the afternoon. While LREF agreement in exact location of the low center has increased slightly compared to previous runs, mesoscale-beta factors will influence and cause mesoscale-alpha forecast discrepancies until a much closer forecast hour is reached.

Ongoing morning storm coverage affecting sky cover and incoming diurnal shortwave radiational budget may cause a slight temporal or spatial displacement affecting northern extent of more unstable air. Coincidental timing of upstream ancillary lee cyclogenesis initially resulting in a double-barrel resemblant low center causing an eventual zonal progression to the afternoon/evening cold front will be another forecast detail to closely monitor as forecast hour nears. While overall confidence is lower to do local forecast area proximity to severe parameters, all hazards will remain possible where severe storms do form.

Slightly Below Seasonable Temperatures Through Next Week:

A Canadian Polar airmass attempts to poke south through the Upper Mississippi River Valley through the middle of next week, raising concerns for frost/freeze initially Tuesday night locally. While initial timing of colder remains dependent on timing of trough ejection, synoptic agreement for colder air settling into region through the middle of the week increases some confidence for near freezing overnight temperatures by the end of the week. Coldest solution in the GFS/GEFS advects the 850mb 0C isotherm through most of Iowa by the end of the work week. Irregardless, current forecast confidence (80%) for slightly below normal temperatures through the end of April.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1227 PM CDT Sat Apr 25 2026

A shortwave trough will move northeast through the area this afternoon and evening. With very dry located below 700 mb, we are only looking at mid and high clouds from this system.

ARX WATCHES/WARNINGS/ADVISORIES

WI...None. MN...None. IA...None.