textproduct: La Crosse

KEY MESSAGES

- Warmer temperatures for today and Monday with highs in the 70s near and south of I-94 on Monday. Cooler temperatures by mid- week with highs in the 40s areawide.

- Isolated strong to severe storms possible on Monday evening and overnight with hail being the primary threat.

- Rain and snow chances (30-50%) for Wednesday night into Thursday.

DISCUSSION

Issued at 1149 PM CDT Sat Mar 28 2026

Today - Monday: Warm, Storm Chances Monday Night

Upper-level ridging and southerly surface flow will dominate the synoptic flow pattern over the next two days resulting in abundant warm advection to push into the region. Consequently, temperatures will feature a robust warming trend for Sunday and especially on Monday with inter-quartile spread in the NBM for high temperatures ranging from the upper 60s to around 80 south of I-94 on Monday afternoon. Overall, while the EC Extreme Forecast Index has fairly decent probabilities (50-70%) for exceeding model climatology, the absence of any shift of tails in the local area suggests that any record warmth is less likely. In any case, with fairly decent mixing in RAP soundings with a low-level dry layer, could certainly be possible for highs to trend closer to the higher percentiles of the NBM on Monday afternoon.

As we head into the evening and overnight hours on Monday, an axis of 850mb moisture transport pushes north into the local area advecting in higher dewpoints overnight into the 50s. As this occurs, instability (MUCAPE values of around 1000-1500 J/kg in the NAM) increases as this moisture transport axis overruns a stationary boundary situated near I-90. The low-levels in NAM/GFS soundings are fairly capped with the bulk of the unstable layer being above 2km. However, with still some elongation to model hodographs, would expect some tendency for elevated storms to begin as a supercellular mode prior to quickly becoming multi-celluar. Given some steeper mid- level lapse rates to around 7-8 C/km and the sufficient shear, thinking that hail will be the primary threat with any strong to severe storms that do develop, contingent on the exact location of where this stationary boundary sets up.

Tuesday - Friday: Turning Cooler, Additional Precipitation Chances

As we head into Tuesday, a cold frontal passage during the daytime hours on Tuesday will bring additional shower and isolated storm potential in addition to ushering much cooler temperatures behind the frontal passage. As a result, inter-quartile high temperatures in the NBM range from the lower 40s to lower 50s across the area, likely uniformly below climatological normals for most. Temperatures for Thursday may trend even cooler with the lower percentiles in the NBM having highs in the 30s for some.

The next feature that bears monitoring comes during the late Wednesday and into Thursday timeframe as a 500mb shortwave ejects from the Central Rockies and into the Central Plains on Thursday. Currently, there remains some deviations in the exact placement of this shortwave as the EC solution tends to favor a slower and weaker trough as opposed to the GEFS solutions which has shown a faster and more amplified trough. This has fairly prominent implications as a faster and more amplified trough favors a stronger and deeper surface low that passes closer to the region unlike the EC counterpart. Overall, cluster analysis of the grand ensemble (GEFS/EC/Canadian ensemble) has higher probabilities (40-70% chance) for measurable snow in the GEFS favored clusters (roughly 1/3 of members) compared to the EC dominated clusters (roughly 2/3 of members) which has low probabilities (10-30%) for measurable snow. Overall, given that we are getting into April as well, thermal profiles would be a question so confidence of how if any wintry precipitation will manifest with this system as it moves into the area is very low. In any case, the grand ensemble (GEFS/EC/Canadian ensemble) has high probabilities (70-90%) for measurable QPF during this period, so confidence is high we will see some precipitation mid-week, just a matter of if any snow will creep its way in.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 545 AM CDT Sun Mar 29 2026

VFR expected through the 29.12Z TAF period. Off surface winds that warranted LLWS mention at KLSE overnight have weakened enough to leave out at 29.12Z TAF issuance. Similar strengthening to nocturnal low level jet tonight raises LLWS concerns at calmer surface wind susceptible locations. Current confidence and strength doesn't meet criteria or warrant inclusion at KLSE TAF site but will require further addressing in subsequent TAF issuances.

ARX WATCHES/WARNINGS/ADVISORIES

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