textproduct: La Crosse

KEY MESSAGES

- Shower chances (30-60%) return on Monday for areas primarily along and south of I-90.

- Cooler than normal conditions are expected throughout much of the week with highs in the 60s.

DISCUSSION

Issued at 245 PM CDT Sun Sep 20 2026

Monday: Shower Chances Return

As we head into the day on Monday, an upper-level trough/cut-off low will eject into the region increasing potential for shower chances during this period. Overall, highest confidence for seeing any precipitation potential generally remains south of I-90 given the position of this upper-level low and where the CAMs largely paint precipitation during the afternoon and evening on Monday. Consequently, much of the higher probabilities (50-80%) in the HREF for measurable precipitation remain largely south of I-90 during this timeframe. Additionally, with the overall weaker Q-vector convergence during this timeframe being the primary forcing regime, probabilities in the HREF for rainfall totals over 1 inch are very low (under 10%).

Tuesday - Friday: Staying Cool and Drier

By the time we get past Monday, northeasterly surface flow and high pressure south of the Hudson Bay will allow for cooler and drier conditions to advect into our region. As a result, median high temperatures in the NBM throughout the week generally remain in the 60s for most of the local area. As we head into Wednesday morning, upper-level ridging will push into the local area which in turn should both allow for a gradual warming trend and clearing skies during this period. Consequently, not seeing much for precipitation chances till later into the week when maybe some shortwave perturbations try to sneak back into the region during the Thursday and Friday timeframe. However, predictability with these waves remains very low at this time. In any case, will have to watch Wednesday morning for some frost potential across north-central WI with median low temperatures in the middle to upper 30s.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1250 PM CDT Sun Sep 20 2026

VFR conditions are expected throughout much of the TAF period with low-level clouds scattering out over the afternoon. Winds will generally remain from the northeast through the TAF period at around 8-15 kts. MVFR cigs may be possible (30-50% chance in the HREF) after 15z across portions of southeast MN and northeast IA as some light rain moves through the region associated with an upper-level system, however confidence in precipitation potential is low at this time.

HYDROLOGY

Issued at 245 PM CDT Sun Sep 20 2026

Some area river sites continue to see rises such as along the Root, Cedar and Turkey Rivers. Volga at Littleport is the only site that remains in moderate flood stage with multiple sites remaining in minor flood stage. Rises at some sites will persist into Monday before stage levels continue to recede throughout the week. The only shot for precipitation in the next few days is on Monday where rainfall totals generally around 0.25" or less are expected which should not contribute to additional rises. Otherwise, mostly dry conditions are expected through the middle of this week.

ARX WATCHES/WARNINGS/ADVISORIES

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