textproduct: La Crosse

KEY MESSAGES

- Areas of fog this morning are possible.

- Isolated to scattered showers and storm are possible this afternoon and evening.

- 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 1202 AM CDT Fri Jul 10 2026

Today: Fog This Morning, Isolated to Scattered Showers and Storms Possible

Conditions are more favorable for fog this morning compared to yesterday morning as both instances had the lighter winds near the surface, but yesterday morning had cloud cover. This morning's forecast is more clear skies which is better for fog to form. Some mid level clouds move in around sunrise that could limit any fog that does form, but the latest HREF has a 30 to 50% chance for less than 0.5 miles of visibility across western Wisconsin and into portions of southeast Minnesota and northeast Iowa. Any fog that does form would dissipate by mid morning.

Similar to Thursday, there is light flow aloft and good instability profiles that support scattered shower and storm potential. While there is a weak wave that moves through during the afternoon and evening, the main question is how dry we are compared to Thursday. There is a good sub-cloud dry layer in the lowest 5kft to 7kft that could inhibit these showers and storms from getting their rainfall to the surface. That being said, recent CAM runs support scattered shower and storm development later this afternoon and evening for areas along and south of I-90. Have gone ahead and introduced 15 to 25% PoPs for this potential.

Saturday-Next Week: Warmer and Drier Through Midweek

Upper level ridging will almost certainly set up across the central CONUS beginning on Saturday and lasting through midweek. 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. Heading into the latter portions of next week, ensemble and deterministic guidance continues to support the ridge breaking down. This in turn would keep the region in northwest flow aloft which is a favorable pattern for waves to pass through. Ensemble members from both the GEFS and EPS begin to bring back precipitation chances Thursday, which reflects this pattern shift.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1228 AM CDT Fri Jul 10 2026

VFR conditions to start the TAF period will give way to the potential for fog, particularly in river valleys with a fairly deep light wind layer, clear skies and lowering dewpoint depressions. As a result, have maintained IFR to LIFR fog at KLSE and KRST for the early morning hours before diurnal mixing by mid-morning causes the fog to lift. There is some potential for 1/4SM at KLSE as a result of valley fog (20-30% chance in the HREF). However, some questions remain regarding northerly flow during the daytime hours that suggest some dry air may be prevalent. Have left 1/4SM out of the TAF for now but will monitor for amendments as needed. Otherwise, fair weather cumulus is expected across the region with perhaps a stray shower or storm possible near and south of I-90 (10-20% chance) during the late afternoon and evening. Winds will generally remain light at around 5 kts or less.

ARX WATCHES/WARNINGS/ADVISORIES

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