textproduct: La Crosse

KEY MESSAGES

- Isolated to scattered thunderstorms are possible this afternoon with lightning and locally heavy rain being the primary hazards.

- Fog is forecast to develop on Friday morning causing lower visibility and potentially hazardous driving conditions.

- 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 103 PM CDT Thu Jul 9 2026

Rest of Today: Low Chance for Isolated Storms Through Early This Evening

West to northwest flow is forecast to prevail over the upper Midwest the rest of the day. This flow will begin to usher in somewhat drier air in the mid levels which should clear out some of the cloud cover that is being observed early this afternoon. Even with the drier air moving in, just enough H700 theta-e may remain in place across portions of the CWA for a few isolated storms to form this afternoon. Even though synoptic forcing is very weak, afternoon highs approaching convective temperatures along with forecast CAPE values of 1500-2000 J/kg may be enough to generate a few storms. Given weak shear values, any storms that are able to form will likely struggle to maintain any cores, so the severe storm threat for today is very, very low. The lack of storm motion combined with long CAPE profiles suggests that these storms may be efficient rain producers. The storm threat should start decreasing this evening as daytime heating ends across the region.

Friday into Next Week: Fog Friday Morning, Drier and Warmer Conditions This Weekend into Next Week

The aforementioned dry mid level air will lead to mostly clear skies tonight into Friday morning. The combination of the light wind, clear skies, and high surface moisture will likely lead to at least patchy fog across much of the area to start the day on Friday. The latest 09/12z HREF shows a wide swath of at least 30-40 percent chance for visibility of 1 mile or less early tomorrow morning with pockets of 60-70 percent chances for 1 mile or less visibility east of the Mississippi River. In addition, river valley fog cannot be ruled out as well, which may lead to dense fog for some locations. For those out traveling tomorrow morning, be prepared for changing visibility.

Upper level ridging will almost certainly set up across the central CONUS beginning on Friday and lasting well into the next work week. Thankfully for MN, IA, and WI, the center axis of the ridging pattern is forecast to remain to the west over the Northern Plains into south central Canada. With the axis to the west, the hottest conditions should also stay west of the FA during this time frame. Even with that being said, high temperatures are expected to be above average for mid July from late this weekend into the middle of next week. Afternoon heat index values could be in the low to mid 90s during the first half of next work week which may lead to some heat related issues for those that are outdoors for extended periods of time. The upper level high sitting over the region should suppress most chances for rainfall during this same time frame.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1226 PM CDT Thu Jul 9 2026

Some intermittent low clouds are remaining over the terminals early this afternoon, but those should begin to lift and clear out over the next few hours. Outside of that potential, VFR conditions are forecast through this evening at the TAF sites. The potential for fog is increasing for tonight with visibility dropping down to MVFR to IFR conditions. Cannot rule out that KLSE sees lower visibility than is currently forecast due to valley fog, but confidence is not high enough to go with lower visby at this time. Any fog that develops should quickly burn off shortly after sunrise with VFR conditions thereafter. Light wind under 10 kts is forecast with this 24 hour period.

ARX WATCHES/WARNINGS/ADVISORIES

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