textproduct: La Crosse

KEY MESSAGES

- Dangerously hot conditions are expected once again this afternoon with heat index values approaching 115. These hot temperatures can cause heat related illnesses.

- Dew points finally start to wane, allowing dangerous heat to dissipate for Tuesday and beyond.

- Next storm chances come late in the week. Severe threat looks low with the main hazard being heavy rainfall.

DISCUSSION

Issued at 157 PM CDT Mon Jul 27 2026

Today - Tonight: Heat Finally Comes to an End

Early this afternoon, heat indices across portions of NE Iowa and SW Wisconsin have soared into the 100-115 degree range as 78-82+ degree dew points pool ahead of a weak cold front sliding southeast across the region. Behind the front across SE Minnesota, dew points have started to drop into the lower 70s, holding heat indices between 90- 102 degrees - still warm but slightly less oppressive. Slightly lower dew points will continue to filter in through the afternoon hours as the front makes its way through the entire area. Dew points through the overnight hours will drop into the upper 50s to 60s area wide, which should feel comparatively better than what we've been experiencing the last few days.

Tuesday - The Weekend: Slightly Less Humid, Rain Chances Late Week

As we move further into the work week, the upper level trough dominating the upper levels across the CONUS will start to retrograde to the west ever so slightly. This will allow slightly cooler northwest flow to prevail across the region. Weak surface high pressure is expected to build in behind the aforementioned weak cold front today, keeping conditions dry through Wednesday. Temperatures will remain on the warm side as temperatures aloft don't see much of a cool down with surface highs in the mid to upper 80s both days.

The upper ridge will continue to slide west and intensify, allowing a shortwave trough axis to rotate south and east out of the northern plains and into the Upper Midwest Great Lakes. This source of lift combined with northward surging gulf moisture will allow for rain chances to return late Thursday into Friday. Soundings for this time period show little to no appreciable shear and weak instability, lending credence to the lack of risk areas across the Driftless Region in any of the machine learning/CSU severe outlooks. The main concern with these storms would be heavy rainfall as pWats look to be approaching 2 inches, especially across Northeast Iowa and SW Wisconsin. WPC has already included our area in a Slight Risk with their Day 5 Excessive Rainfall Outlook to highlight this potential. Rain chances look to gradually come to an end through the day on Saturday with dry conditions expected for the rest of the weekend. Temperatures Friday and Saturday will be slightly cooler given the widespread rain chances with highs in the upper 70s to low 80s.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1226 PM CDT Mon Jul 27 2026

VFR conditions are expected across much of the area over the next 24 hours with 2 exceptions: sporadic BKN ceilings around 2500 feet may (20%) occur over the next 3-4 hours and then some valley/fog stratus may occur in the Wisconsin Valley around OVS overnight. Otherwise, winds will generally be out of the northwest today and will turn clockwise to northeast by the end of the period.

ARX WATCHES/WARNINGS/ADVISORIES

WI...Extreme Heat Warning until 9 PM CDT this evening for WIZ041>044-053>055-061. Heat Advisory until 9 PM CDT this evening for WIZ032>034. MN...Extreme Heat Warning until 9 PM CDT this evening for MNZ096. Heat Advisory until 9 PM CDT this evening for MNZ079-086>088- 094-095. IA...Extreme Heat Warning until 9 PM CDT this evening for IAZ008>011-018-019-029-030.