textproduct: La Crosse

KEY MESSAGES

- Highs in the upper 70s to lower 80s for this weekend gives way to highs in the 80s areawide for the upcoming week.

- Periodic shower and storm chances this weekend and into next week. Highest confidence (20-50% chance) for any showers and storms is currently west of the Mississippi River for tonight through Monday.

DISCUSSION

Issued at 100 PM CDT Sat May 30 2026

Rest of Today - Sunday: Seasonable, Some Precipitation Chances

Overall a fairly pronounced omega ridging pattern is in place across the region for this weekend which has resulted in relatively dry conditions and seasonable temperatures. However, as we head into the overnight hours for tonight, a trough situated over the Rockies will pivot northward through the Great Plains bringing some weak shortwave impulses through the mid-level flow tonight. As a result, some of the CAMs develop some shower activity generally near the vicinity of I-35 overnight. Overall, instability is fairly limited with dewpoints around 40 degrees overnight so really not expecting much of thunder out of any precipitation. However, given that the HREF has respectable probabilities (30-70%) west of the Mississippi River for measurable rainfall, thinking some showers are feasible. As we head into the daytime hours on Sunday, with the aforementioned trough pushing through the area, additional weak shortwave impulses move through the region and continue into the overnight with the HREF having medium probabilities for measurable precipitation (20-50%) during this timeframe. In spite of the profound ridge overhead, temperatures will remain relatively seasonable for the weekend with highs in the 10th to 90th percentile spread of the NBM ranging from the middle 70s to middle 80s, mostly due to persistent easterly flow in the low- level.

This Week: Slight Warmup with Periodic Shower and Storm Chances

As we begin the upcoming work week, Monday will feature some small storm chances as a weak boundary west of the local area initiates storms into a narrow corridor of MUCAPE values reaching 750-1500 J/kg across south-central MN. Overall the forcing in this regime is fairly questionable, however if storms can sneak their way into portions of southeast MN and northeast IA, mid-level lapse rates of around 6.5-7 C/km and DCAPE values approaching 900 J/kg would suggest at least some potential for small hail or gusty winds. Overall though the grand ensemble (GEFS/EC/Canadian) has respectable (50-80%) probabilities for measurable preciptiation in portions of southeast MN and northeast IA so cannot rule out some precipitation sneaking in during the afternoon and evening, however it is uncertain if there will be enough shear and other severe ingredients in place for storms to pose any hail or wind risk.

Otherwise, the start of the week will feature a synoptic ridge amplifying yet again across the area for Tuesday and Wednesday resulting in southerly surface flow to return 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 /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1136 AM CDT Sat May 30 2026

VFR conditions are expected through the TAF period with bkn high clouds expected. Winds will begin the TAF period at around 10-15 kts from the east/southeast before diminishing to around 10 kts overnight and into the day on Sunday. There is a small chance (10- 20%) for a passing shower overnight and into the day on Sunday at KRST, however confidence for any category reductions at KRST from this is very low (under 10% chance) at this time so have opted to not include in the TAF.

ARX WATCHES/WARNINGS/ADVISORIES

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