textproduct: La Crosse

KEY MESSAGES

- Storm chances increase this evening through tonight with a low chance for severe storms north of I-90.

- Afternoon temperatures remain in the upper 70s to low 80s each day and rain chances increase this upcoming weekend.

DISCUSSION

Issued at 1242 PM CDT Tue Aug 25 2026

This Afternoon through Tonight: Strong/Severe Storm Potential

Visible satellite imagery early this afternoon depicts an upper level low pressure system across southeastern Manitoba and is trekking off to the southeast. To the south of the low, a weak cold front is racing southeast with westerly to northwesterly winds in its wake. Showers and storms continue to form just to the west of Lake Superior at this time, but cloud cover is decreasing in coverage and temperatures across northeastern Minnesota into western Wisconsin should begin to rise. The increasing temperatures should lead to increasing instability over the next few hours.

As the weak surface front interacts with the unstable airmass, synoptic lift and surface lift should be sufficient enough to generate isolated to scattered storms along and just ahead of the front. Just how far south the storms can generate along the boundary remains uncertain, mainly due to lesser instability further south along with higher CIN. There will be sufficient ingredients in place for these storms to become severe, with damaging wind gusts and large hail being the primary hazards. Given how late the storms are forecast to potentially impact the northern counties in the CWA, 7-8 PM if not later, nocturnal cooling will increase CIN and a quick decrease in intensity is expected with eastern extent. Shower and storm chances will continue through the overnight hours for areas in Wisconsin, but the severe threat should quickly decrease after sunset.

Wednesday through This Weekend: Seasonal with Weekend Rain Chances

Forecast models depict upper level ridging should remain to the west of the Upper Midwest through much of this forecast period. Cooler air will keep temperatures right around average for late August and afternoon highs should be in the upper 70s to low 80s each day. As the ridge flattens this weekend, this will open the door for disturbances to round the top of the ridge and they may generate showers and storms across portions of the Northern Plains towards the Great Lakes. The highest chances are Saturday and Sunday for any rainfall across the area.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1215 AM CDT Wed Aug 26 2026

Main aviation impacts remain in the immediate term as broken line of storms shifts southeast through the forecast early in the overnight hours. Impacts expected to remain east and south of both TAF sites (KLSE/KRST).

Scattered showers and storms possible primarily north of Interstate 94 through Wednesday. Responsible low level cold air advection will increase northwest winds across the forecast area as well.

ARX WATCHES/WARNINGS/ADVISORIES

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