textproduct: La Crosse

KEY MESSAGES

- Dry through Friday, precipitation and storm chances increase through the weekend. - Low confidence (<15%) for storms mostly Sunday and Monday.

DISCUSSION

Issued at 1229 AM CDT Thu Aug 27 2026

Precipitation & Storm Chances Increase Through The Weekend:

Dry conditions expected through the rest of the work week as eventual low level moisture transport excites through the Central Plains overnight Friday into Saturday, poking through southwest into central Minnesota. Similar to previous forecasts, the GEFS long term global ensemble mean solution suggests a stronger lobe of positive mid level vorticity advection running the ridge axis, resulting in earlier aforementioned precipitation chances initially overnight while EPS solution delays onset until the late morning/early afternoon Saturday. Although, eventual and perpetual stronger mid level vorticity advection through the weekend in the EPS results in higher probabilities (100%) for 0.1" of rainfall in 24 hours as the GEFS remains <80% until east of the forecast area in eastern Wisconsin on Sunday.

Storm Probabilities Sunday & Monday:

Concurrent probabilities between and within long term global ensembles has increased for instability settling near or over the forecast area for Sunday, increasing local storm concerns. While relatively higher spread seen in EPS MUCAPE, both the GEFS and EPS exhibit joint probabilities of 30-60% for MUCAPE/SBCAPE of 500+ J/kg with 30+ kts of 0-500mb bulk wind shear over the forecast area. Although, associated soundings suggest a low level capping inversion potentially limiting access to increased instability off the surface until Monday when long, skinny profiles limit higher value tail and consequently overall ensemble probabilities. All accompanying machine learning convective hazard forecast models limit local probabilities to 15% given ensemble spread and conditional pattern. Further confidence challenge stems from domino effect of initial storm coverage(s) affecting subsequent storm initiation location(s) and strength(s) through the weekend.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1229 AM CDT Thu Aug 27 2026

Other than some scattered 3-5K diurnal cumulus clouds skies will be clear. Light northwest winds will continue to bring dry air into the region. This will greatly limit valley fog development overnight tonight and on Thursday morning.

ARX WATCHES/WARNINGS/ADVISORIES

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