textproduct: La Crosse

KEY MESSAGES

- Highs in the upper 70s to lower 80s for today and Monday give way to highs in the 80s areawide for the rest of the week.

- Periodic shower and storms possible (20-40% chance) through Monday, mainly west of the Mississippi River.

DISCUSSION

Issued at 1217 AM CDT Sun May 31 2026

Today - Monday: Light Shower/Storm Risk, Seasonable Temps

A low to mid-level tropospheric theta-e ridge axis has been meandering northeastward over the last half day or so across Iowa, with the leading theta-e advection corridor serving as a focus for light showers overnight west of the Mississippi River. These showers are fighting dry low-level easterly flow, limiting the wetting nature of the showers. This pattern lingers through the day, with multiple waves of light showers--mainly west of the Mississippi River--into early Monday morning as multiple perturbations lift northward around a nearly zonally- oriented trough stretching the I-90 corridor from the west coast to Wisconsin. Overall rainfall amounts will do little to alleviate the dry concerns for much of the region.

The increasing clouds attendant with this system have tempered the high temperature forecast for today and Monday, with highs in the mid-70s to low 80s today and Monday.

Questions linger about the degree of storm coverage and location for Monday afternoon and evening. There has been a drier shift in the Grand Ensemble guidance with both the deterministic EC/GFs showing upper level height rises potentially squashing development. The MUCAPE axis also looks to linger more off to the west. but not by far. Steep boundary layer lapse rates under these storm bases and more linear hodographs could promote a wind/hail threat--if storms were to form. The extended runs of the ARW/HRRR are devoid of storms at this range, though the RRFS is more bullish on storms east of I-35. These storms seem more contingent on the presence of a stronger (convectively reinforced?) boundary laying out over the area in the afternoon, a feature that could easily evolve over the next 24 hours.

Rest of the Week: Dry Start, Showers Late in the Week

Tuesday and Wednesday will feature a synoptic ridge amplifying yet again across the area, resulting in southerly surface flow returning towards mid-week. As a result, expecting highs to warm slightly with temperatures reaching into the middle to even some upper 80s come Wednesday. Additionally, with the ridge axis firmly overhead for Tuesday and much of Wednesday, minimal precipitation chances are noted across ensemble and deterministic guidance.

However, deterministic guidance generally agrees that this ridge breaks down going into late week resulting in a more zonal flow pattern. Consequently, various shortwave perturbations as shown in guidance with low confidence on exact timing and location. Regardless, probabilities increase fairly dramatically (50-90%) for measurable precipitation in the grand ensemble (GEFS/EC/Canadian ensemble) during this period so confidence is certainly increased for at least some precipitation by late week.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1217 AM CDT Sun May 31 2026

Potential for light rain west of the Mississippi River continues overnight into Sunday (20-40%), but impacts associated with them are expected to be minimal. VFR ceilings remain across the region, around 5kft in showers and 10kft or higher elsewhere. Southeast prevails as the predominant wind direction through the TAF period, generally 5-15KT during the day Sunday, strongest west of the Mississippi River.

ARX WATCHES/WARNINGS/ADVISORIES

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