textproduct: La Crosse

KEY MESSAGES

- Isolated showers possible in north-central WI this afternoon. Additional rain likely (50-80% chance) in northeast IA and southwest WI on Sunday.

- Showers and storms likely (60-90% chance) on Tuesday afternoon through the overnight.

- Continued pleasant temperatures this weekend and into next week with highs in the 70s for most locations.

DISCUSSION

Issued at 1248 PM CDT Sat Jun 20 2026

Rest of Today - Sunday: Precipitation Chances & Staying Slightly Cooler Than Normal

Cooler than normal temperatures on are tap throughout the remainder of the weekend as northwesterly mid-level flow into the region will continue to perpetuate a cooler airmass into the region. Consequently, guidance generally agrees on keeping high temperatures in the middle to upper 70s across much of area this weekend. Cannot rule out some showers (10-20% chance) with the northwesterly flow regime across portions of north-central WI as shown in a few of the CAMs. However, would not expect any meaningful rainfall from these during the afternoon and early evening.

As we head into Sunday, a 500mb shortwave in the central Rockies pushes eastward towards the mid-Mississippi River Valley during the daytime hours on Tuesday. As this occurs, expecting some chances for stratiform rain to work its way into areas primarily south of I-90. Overall, probabilities in both the LREF and HREF are fairly high (50- 90%) south of the MN state line for at least measurable rainfall, a slight northward shift from previous forecast cycles. Consequently, have increased precipitation chances accordingly across portions of northeast IA and southwest WI. However, given fairly limited instability in the recent RAP, really not expecting much for heavier rainfall amounts with the stratiform region in the local area north of the surface low associated with the aforementioned shortwave. As a result, probabilities (20-50%) for 0.5" or greater of rainfall in the recent HREF are not overly high and are confined to a Platteville, WI to Oelwein, IA line on southward.

Monday - Friday: Staying Pleasant, Shower/Storm Chances Mid-Week

By the time the upcoming work week rolls around, continued quasi- zonal to northwesterly flow will allow for temperatures to remain roughly steady-state with highs keeping to the 70s for much of the work week. The main feature to watch for any precipitation potential would be on Tuesday as an upper-level shortwave trough descends from the Northern Rockies and into the Upper Midwest. As this occurs, an associated cold frontal passage will swing through the region, instigating a period of showers and storms for the afternoon and into the overnight hours on Tuesday. Confidence for measurable rainfall during this period is quite high (over 90% chance) in the grand ensemble (GEFS/EC/Canadian), however joint probabilities for MUCAPE over 500 J/kg and 30 kts of bulk shear are fairly low (0-30%). Additionally, much of ML/AI severe weather outlook guidance does not paint much for probabilities (generally 5% or less) of severe weather over the region. That being said, fairly favorable upper-level jet streak dynamics would suggest that you could get some more favorable deep-layer shear and materialize some localized storm organization if it overlaps with any marginal instability axis. However, given that the position and timing of when this trough swings through the region differs slightly across deterministic guidance, confidence in how any severe threat is very low at this point. In any case, seems fairly likely we will see precipitation during this period with very low confidence on if any severe weather potential will manifest.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1218 PM CDT Sat Jun 20 2026

VFR conditions expected through this TAF period at LSE/RST. Breezy NW winds will diminish toward sunset as high pressure drifts overhead tonight, swinging winds around to the east- southeast for Sunday. Rain chances will spread northward Sunday morning but are looking more likely to stay confined mainly south of I-90.

ARX WATCHES/WARNINGS/ADVISORIES

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