textproduct: La Crosse

KEY MESSAGES

- Dry and pleasant today.

- Next round of storms rolls through Thursday afternoon and night with the storm threat lingering potentially into Friday. Overall impacts look to be minimal.

- Seasonal temperatures remain on tap through at least the end of the week.

DISCUSSION

Issued at 715 AM CDT Wed Aug 19 2026

Dry Today:

A cooler, drier airmass works through the forecast area today concurrent with anticyclonic flow solidifying drier conditions.

Storm Chances Thursday:

The high confidence in dry conditions decreases through Thursday as upper level extratropical cyclonic flow, seen on GOES water vapor imagery loops tonight over the Canadian Rockies enhances low level, moisture-laden flow through the Upper Mississippi River Valley. While current timing and strength of advecting flow and forcing abates higher severe storm probabilities northwest of the local forecast area, a slight eastern shift in machine learning severe hazard probabilities over recent runs now grazes the western periphery of the local forecast area with 5-15%. Therefore, while current confidence is lower (<15%), farther eastern shift in model solutions will be the initial locally impactful detail to remain cognizant of in coming forecasts.

Heavy Rain Chances Friday:

While /most/ long term global ensemble models and their deterministic counterparts agree on the accompanying low center remaining relatively benign initially through Thursday, glancing locally northern counties in west-central and central Wisconsin with highest (100%) precipitation probabilities, deepening of the accompanying lingering trough has increased probabilities for heavier (0.1" & 0.5" /24hrs) rainfall across the northern /half/ of the forecast area through Friday and into the weekend in most recent ensemble runs. Should Thursday nights storm advection result in more eastern solution to the accompanying frontal boundary, this threat would shift east, potentially east of the local forecast area. Therefore, although current WPC Excessive Rainfall Outlooks don't depict much of a threat, will be subsequent detail to monitor in coming forecasts. Severe storm threat remains conditional on clearing skies permitting low level diurnal instability to build as long, skinny instability profiles in individual LREF member plumes exhibit stunted hodographs until the stronger mid-upper level winds Friday night into Saturday.

Mostly Cool & Dry Weekend:

In the wake of Friday's storm potential, a cooler weekend is expected with daytime highs from the 70s to low 80s through Monday.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 535 AM CDT Wed Aug 19 2026

VFR conditions are expected throughout much of the TAF period aside from the potential for initial valley fog/low-stratus at KLSE this morning. Currently, many river valley locations in southwest WI are noting vsbys of 1/2sm to 1/4sm, however mid-level clouds aided in improving vsbys at KLSE. It is unclear if redevelopment will occur at KLSE, however satellite trends do not appear overly favorable as of 1030z. In any case, fog that does develop will dissipate by mid-morning leaving VFR conditions with winds generally being light and variable throughout the TAF period.

ARX WATCHES/WARNINGS/ADVISORIES

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