textproduct: La Crosse

KEY MESSAGES

- Dry conditions and cooler temperatures are expected through Friday with daytime highs from the 70s to low 80s.

- Thunderstorm chances return along with more summer-like heat this weekend into early next week.

DISCUSSION

Issued at 244 AM CDT Tue Jul 21 2026

Tuesday through Friday: Below Average Temperatures and Dry Conditions

A 500mb trough will be in place over the northeast with the center of high pressure remaining over the southern High Plains through Thursday-Friday. This pattern leads to northwest flow over the Upper Mississippi River Valley resulting in a cooler air mass in place locally. This cooler air mass will initially be noticeable today behind a cold frontal passage overnight. Below average temperatures, in the 70s to lower 80s, are expected through the work week as the cooler air mass remains in place. There is strong ensemble agreement in this scenario panning out with 25th to 75th percentile temperature differences only upwards of 5 degrees through Saturday. Negative theta-e advection is forecast during the rest of the week which will not be favorable for the development of showers or storms.

This Weekend into Next Week: Thunderstorm Chances Return

The aforementioned upper level center of high pressure is expected to move over the Intermountain West over CO/NM this weekend with a jet stream rounding the top of the ridge from the Canadian Prairies into the Midwest during this time frame. Mid level moisture should return to the region and with embedded H300 shortwaves progressing through the northwest flow over the CWA, shower and thunderstorm chances are likely to return. Details are uncertain and will change as we get closer to the weekend, but there is the potential for severe thunderstorms on Sunday as instability increases over the area. In addition to the storm chances, WAA should lead to temperatures increasing back into the 80s to low 90s Saturday through Monday.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 600 AM CDT Tue Jul 21 2026

Besides increasing cloud cover bringing potential for temporary MVFR ceilings later this morning into the early afternoon, VFR expected across most of the local forecast area through the 21.12Z TAF period.

ARX WATCHES/WARNINGS/ADVISORIES

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