textproduct: La Crosse

KEY MESSAGES

- Periodic storm chances continue from Sunday through midweek. There may be some severe risk with each storm chance, but confidence in the details are low.

- Temperatures remain near normal through midweek with a cooling trend for the latter half of next week as the better storm potential shifts south of the forecast area.

DISCUSSION

Issued at 1254 AM CDT Sat Aug 8 2026

Today - Sunday: Dry Today, Storms for Sunday

After a trough axis moved past the area yesterday evening, the flow pattern across the region shifts to northwest flow for today. With the northwest wind shift, there is a low potential for smoke to come back, however this should mostly stay aloft and not impact the near surface area. Focusing on the precipitation chances, the boundary that as helping storms initiate for yesterday has shifted south. This will keep any storm chances at bay and result in a pretty nice day with highs in the mid 70s to low 80s. Dewpoints decrease compared to the past couple of days into the mid 50s to low 60s. By later this evening, a low forms just of the central Rockies. This helps to push the boundary back northward. In doing so, southwesterly flow returns and dewpoints increase back into the mid 60s. Incoming PWATs are in the 1.5 to 2.0" range so storms that do form would be efficient rain producers in short order. Now there is good model agreement on a decent wave moving through the Upper Midwest Sunday morning, however the convective evolution is uncertain. Given that we are in northwest flow aloft, this could favor a MCS moving through the area. Most CAMs do show some sort of storm complex impacting portions of the forecast area Sunday morning with differences in exact location and intensity.

Heading into the afternoon and evening on Sunday, the low that forced the boundary further north for the morning, shifts further east and creates another push of southwesterly flow, keeping PWATs in the 1.5 to 2.0" range and dewpoints in the upper 60s to mid 70s. While some of the CAMs are beginning to show signs of convection by the later evening, uncertainty resides in how convection will go. If we can clear out fast enough, then the atmosphere could recover, which some models are showing that owing to precipitation ending by early afternoon and convection not forming until the later evening hours. Other models have most of the area under a strong CAP into the evening. Needless to say that even a day out the storm evolution is quite uncertain for Sunday morning and evening.

Monday - Tuesday: Continued Storm Potential

The same boundary that will impact precipitation chances this weekend is expected to sit somewhere between central Iowa and southern Minnesota. This will provide a few opportunities for storms to impact this area. Looking at LREF clustering, all of them have another decent wave pegged to move through the Upper Midwest Tuesday morning, however similar to this weekend, details regarding early next week's storm potential is quite uncertain, but will be refined in the coming days.

Wednesday - Saturday: Cooler and Drier

Ensembles are in good agreement that a cooler airmass shifts southward into the Upper Midwest for the latter portions of next week. This will bring temperatures down into the low to mid 70s. The better rain chances remain to our south as the front looks to stay further south, however with this front not too far away, rain chances could increase if this front were to move back north. Currently, there are some GEFS and EPS members showing increased rain chances for this period, however the majority of them are dry. The better rain chance is looking like Friday into Saturday.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 544 AM CDT Sat Aug 8 2026

Mostly VFR conditions expected for the next 24 hours at the terminals. Isolated instances of valley fog have been noted across the Mississippi and Wisconsin River Valleys and their tributaries this morning but these should burn off in the coming hours after sunrise. Light northwesterly winds will back to a more southerly direction through the day but speeds should stay at less than 10 kts through the period. Have introduced a PROB30 at both terminals for the end of the period as chances for showers and storms increase late overnight into the early morning hours Sunday.

ARX WATCHES/WARNINGS/ADVISORIES

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