textproduct: La Crosse

KEY MESSAGES

- Isolated thunderstorms are possible this afternoon through early this evening with lightning and locally heavy rainfall being the primary hazards.

- Warmer and drier conditions are forecast next week with heat index values in the lower to mid 90s which may result in some heat related issues for those that are outdoors.

DISCUSSION

Issued at 1249 PM CDT Fri Jul 10 2026

Rest of Today into Tonight: Low Chances (10-20%) for Isolated Storms Through Early This Evening

Conditions for this afternoon through tonight are nearly identical to yesterday. Upper level ridging is going to start to become more amplified over the Northern Plains later on today with northwest flow in place over the CWA. The flow will once again be very weak for the rest of today as high pressure begins to build in aloft. There will be another low chance (10-20%) for isolated showers or storms to develop across the region by peak heating this afternoon. Even though there is some mid level dry air in place right now as shown in forecast soundings, H700 theta-e advection will move in as peak heating is achieved this afternoon. Synoptic scale lift will be weak at best so any storms that do form will be diurnally driven later on today and should quickly dissipate near sunset this evening. Instability values upwards of 1500 J/kg MLCAPE support a potential for lightning and moderate to heavy rain with any storms that are able to form. Storms will be pulse like again today as shear is pretty much non-existent so organized convection leading to severe storms is not forecast for today.

Clearing skies are expected overnight along with a very light wind out of the east. The clearing skies should lead to good radiational cooling tonight and RH values should reach 90 percent or higher again tonight. These atmospheric conditions may lead to patchy fog developing on Saturday morning. With that being said, have added in some patchy fog, mainly for west central Wisconsin as blended model guidance depicts that area has the best potential for visibility to drop down to a mile or less.

This Weekend into Next Week: Drier and Warmer Conditions Through Midweek

The aforementioned ridge of high pressure will elongate and become more established across the central CONUS this weekend into early next week. As this occurs, an H300 low pressure system is forecast to undercut the ridge and move west towards the southern High Plains during the first half of the next work week. With the CWA being to the north of the low and east of the high, northerly to easterly flow is expected during this time frame. Thankfully, the main axis of summer heat should stay west of the area during this time frame. Hot temperatures are still expected however, with Monday, Tuesday, and potentially Wednesday featuring heat index values in the low to mid 90s. These hot temperatures and humidity can lead to heat related illnesses for those that are outdoors for extended periods of time.

The upper level pattern is not favorable for shower or thunderstorm development this weekend into the first half of next week as the high pressure should keep storm chances suppressed. The ridge may start to weaken by late next week as low pressure systems dig south across portions of Canada. If this occurs, a return to northwest flow may set up over the Upper Midwest which would open the door to shower and storm chances returning to the region along with slightly cooler temperatures.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1222 PM CDT Fri Jul 10 2026

Low clouds remain over KLSE early this afternoon with MVFR ceilings still being observed. This cloud deck has slowly been lifting and becoming more scattered so the expectation is that VFR conditions will return in the next hour or two. Isolated showers or thunderstorms may form later this afternoon into early this evening. Chances for storms are much too low to mention in the TAFs right now, but will amend if anything forms near the terminals. There are also low chances for patchy fog to develop near the sites for a brief period near sunrise on Saturday morning. Confidence is not high enough to mention in the TAF for now, but will keep a close eye on that potential. The wind over the next 24 hours will remain mainly out of the east to southeast and should stay under 10 kts.

ARX WATCHES/WARNINGS/ADVISORIES

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