textproduct: La Crosse

KEY MESSAGES

- Rain exits to the east this evening for portions of northeast IA and southwest WI.

- Showers and storms likely (70-95% chance) on Tuesday and into Wednesday.

- Continued cooler than normal temperatures this week with highs in the 70s for most locations throughout much of the upcoming work week.

DISCUSSION

Issued at 111 PM CDT Sun Jun 21 2026

Rest of Today - Monday: Rain Exits this Evening South of I-90, Staying Cooler than Normal

Rain across portions of northeast IA and southwest WI this afternoon will gradually shift east into the evening as the surface low responsible pushes eastward into the Ohio Valley during this timeframe. Overall, rainfall totals this afternoon and into this evening suggested in the recent HREF have decreased from yesterday's forecast cycle due to a slight southerly shift in the track of the surface low. As a result, while probabilities for measurable precipitation remain very high (70-100%) across portions of northeast IA and southwest WI, the probabilities for 0.25" of rain or greater are lower (10-40% chance). All said, not likely to be an overly impactful rainfall this afternoon.

Otherwise, quasi-zonal to northwesterly flow combined with weak surface high pressure building into the area for Monday will lead to a fairly nice day with highs in the middle 70s to near 80 degrees and minimal sky cover. Definitely a good day to get outdoors and enjoy the cooler temperatures for this time of year!

Tuesday - Friday: Showers/Storms Likely Tuesday and Wednesday, Continued Cooler than Normal Temperatures As we head into the middle of the week, an upper-level shortwave trough will descend from Alberta/Manitoba, Canada and into the Northern Plains during the evening hours on Tuesday. As this occurs, a developing surface low pressure center and attending cold front will translate during the evening and into the overnight hours on Tuesday across the Upper Midwest. This combined with a weak axis of 850mb moisture transport will likely be sufficient enough to instigate a region of showers and storms along and ahead of this front. Consequently, probabilities for measurable precipitation in the grand ensemble (GEFS/EC/Canadian ensemble) are quite high (over 95% chance) during this period. The question that remains is if there is any severe potential with this feature. Overall, the current progged moisture transport axis and precipitable waters in deterministic guidance are not overly impressive with precipitable water values of around 1.40", roughly the 75th percentile for KDVN sounding climatology for this time of year. Consequently, instability seems to be relatively limited over the local area with the NAM/GFS keeping MLCAPE values under 1000 J/kg. This combined with the more favorable shear associated with the upper-level shortwave currently waiting until the overnight to push into the region, keeps confidence in severe potential low at this point. This is reflected in much of the AI/ML guidance which keeps probabilities for any severe weather very low (5% chance or less). That being said, any changes in the strength and timing of the upper-level shortwave could have implications for how any severe weather would unfold. Regardless, after showers and storms for Tuesday and into Wednesday, temperatures will remain cool into Thursday with continued northwesterly flow behind this system before beginning to warm slightly into Friday.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1200 PM CDT Sun Jun 21 2026

VFR conditions are expected to continue at LSE/RST through this TAF period. Rain impacts should stay to the south today with a small chance (30%) for MVFR visibilities/ceilings clipping Fayette/Clayton/Grant counties. Some guidance hints at fog potential late tonight over the cranberry bog areas and the Wisconsin River valley as skies gradually clear and winds become calm.

ARX WATCHES/WARNINGS/ADVISORIES

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