textproduct: La Crosse

KEY MESSAGES

- The risk for showers and storms increases through the day from west to east, with a few stronger storms that could produce heavy rain this afternoon and evening.

- Additional rounds of stronger to possibly severe storms for Friday afternoon and evening, but how storms unfold today will play a large role in the location and hazards with storms on Friday.

- Temperatures warm up into the mid 80s to low 90s into early next week.

DISCUSSION

Issued at 545 AM CDT Thu Jun 4 2026

Today's Storm/Heavy Rain Potential:

A decaying band of showers is moving into southeastern Minnesota at sunrise and will continue to dissipate by mid-morning. Impacts from these showers should be minimal. These showers demarcate the leading edge of a lower tropospheric moisture axis that will serve as the instigator for renewed shower and storm development as we head into the afternoon.

Instability might be a bit patchy if cloud cover holds, but some sporadic 500-1500 J/kg of MUCAPE won't be unheard of by this afternoon. As an area of 30-45 kt mid level flow moves overhead to help enhance the shear, this will create a marginally favorable environment for strong to severe thunderstorms. Lapse rates will be pretty weak overall and dense cloud cover will likely prevent widespread destabilization but with 25-35 kts of effective shear, multicell clusters will be more favored. Severe wind gusts and marginally large hail look to be the main threats with the strongest storms.

There is a low threat for flooding with these storms as WPC has included our area in their Marginal Risk for Excessive Rainfall. South to southwesterly flow throughout the low to mid levels on the backside of a stout surface high across the eastern seaboard will lead to large scale moisture transport into the Northern Plains and Upper Midwest through the day today. PWats will be in the magnitude of 1.25-1.75 inches (around the 98th percentile for NAEFS) which means this will lead to effective rainfall producers with any shower or storm. And if there is any training activity, which is not out of the realm of possibilities, that could lead to some small scale flooding concerns. The good news is that with recent dry conditions our rivers and land should be able to take a decent amount of rain before concerns start to arise.

Friday Severe Potential:

The severe potential looks a bit more interesting for Friday. Unfortunately, it also looks a lot more convoluted than Thursday. Lets break it down: It all starts with if there's any residual convection from the Thursday night activity and if there is, where is it and how long does it last? In all likelihood it wouldn't be particularly strong at that point but how will the outflow from that convection impact the expected destabilization later in the afternoon. Most models are thinking this residual convection shouldn't be a problem and destabilization shouldn't be hindered. I am personally more skeptical about this as the atmosphere may be too overturned. With an MCS like feature moving through the night before and a lack of a low level jet to bring back some of that appreciable low level instability, how readily available will the atmosphere be up in our neck of the woods? A lot of things will depend on how the overnight convection pans out so there's still plenty of uncertainty in regards to the potential outcome.

The reasonable "worst case scenario" would be like what many 00Z hi- res models are indicating - widespread destabilization by the afternoon with 1500-2500+ J/kg MUCAPE as dew points climb into the mid 60s. In addition to a surface cold front, a mid level shortwave trough will add additional upper level support as it moves through the Northern Plains into the afternoon and evening hours. Effective shear isn't the best with this system but 25-40 kts are still more than enough to support multicell to supercell structures. Storms would start to develop around the late afternoon as the capping inversion along and ahead of the front gradually erodes and move east. All hazards would be possible with initial supercells but large hail and damaging winds look to be the primary threats as the low level jet will be displaced to our south and west, keeping the greater conditional threat for tornadoes with that. Similar to Thursday, there is a continued threat for heavy rain leading to instances of flooding, primarily if storms were to start training. Another possibility is if any portion of the frontal boundary becomes slightly more east/west oriented as that would allow for even more training storms.

This Weekend Into Mid Next Week: Getting Hotter with Continued Low Rain Chances

Conditions look to become more benign by the weekend as significant ridging starts to take shape in the upper levels. The main point of note will be the continued upward climb in high temperatures. While highs this weekend will be warm in the mid to upper 80s, it only gets worse into early next week as dew points climb into the upper 60s and low 70s. Highs will start flirting with the 90 degree mark on Monday before surpassing it on Tuesday and beyond. Temperatures by midweek could start approaching the mid to upper 90s and with dew points in the 70s, this could mean we have to start thinking about the potential for heat headlines. There's still a lot that can change but it's looking awfully summery next week and not in the best way. Low chances for rain will continue each day, even with ridging overhead given the abundance of moisture present and potential for a few weak disturbances aloft.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 545 AM CDT Thu Jun 4 2026

VFR conditions are expected through at least midday before showers and storms increase in coverage through the afternoon and evening areawide, gradually pushing eastward into Wisconsin overnight. There may be some light showers in the morning from a decaying band of storms to the west, but aviation impacts appear to be minimal. Expect localized pockets of MVFR to IFR conditions in the stronger storms. Winds remain from the south to SW at around 5-15 kts, strongest west of the Mississippi River.

ARX WATCHES/WARNINGS/ADVISORIES

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