textproduct: La Crosse

KEY MESSAGES

- Precipitation chances graze local counties in southeast Minnesota and central Wisconsin overnight through Monday night.

- Potential (40-80%) for more widespread precipitation Wednesday night into/through Thursday morning. Much spread in models attributed to questions regarding overall forcing and available moisture.

- Low confidence (30-50%) in additional precipitation chances this weekend into early week.

DISCUSSION

Issued at 156 PM CDT Mon Oct 26 2026

Today - Tuesday: Light Rain North of I-90

Light rain showers have moved into northern portions of the Upper Mississippi Valley early this afternoon along the leading edge of a mid level vorticity lobe moving through the North Central Plains. Showers across our area have remained light overall given the low level dry air and sub-1 inch pwats across much of the region. Deeper, more quality moisture remains well to our west across the Siouxland and into the Central Plains where stronger moisture transport has also set up. As the vorticity lobe and associated weak surface low move off to the northeast, the showers will gradually lift into Northwest/North Central Wisconsin through the overnight hours into early tomorrow morning. Though a few sprinkles may linger across our area, a mostly dry forecast is expected for tomorrow. With dense cloud cover expected through tomorrow evening, lows for tonight have been tempered a bit as radiational cooling shouldn't be as effective. Also dropped temperatures a few degrees for tomorrow with continued cloud cover likely limiting heating, similar to today.

Wednesday - Thursday: Warmer, Increased Rain Chances

Though upper level flow looks to become more zonal by mid-week, a subtle shortwave trough/trough axis is expected to move to our north late Wednesday into Thursday with weakly west/southwest flow ahead of this. At the surface, a weak but deepening surface low will push east across the Canadian Plains and into Ontario. A cold front will extend to the south into Northern Plains early Wednesday morning. As this trough axis and corresponding cold front move east, they will run into a more moist airmass with deeper northward flowing gulf moisture. This influx of gulf moisture into the region from southerly low level flow could allow for precipitable water values to climb upwards of 1.5 inches - roughly 150-200% of normal or 2 standard deviations higher than average for late October around here. With semi- favorable upper level synoptics, low level forcing from the surface front, and decent moisture, this looks to be our best chance for rainfall overnight Wednesday into Thursday. Even with the decent moisture for October standards, the very progressive nature of the front will keep any heavy rain concerns at bay with most locations likely only seeing up to 0.25 inches with this. Once the front moves through, rain chances should largely come to an end with dry conditions for Thursday.

Temperatures Wednesday will be the warmest of the long-term with highs in the low to mid 70s, which could break records at both Rochester and La Crosse. Post frontal temperatures Thursday will be back into the 60s.

Friday - The Weekend: Off/On Rain, Mild Temps Continue

Confidence in weekend precipitation chances wane a bit more as they will rely more on an appendage moving through the southwest flow aloft - away from a broad upper low across the Western CONUS. A broad wave of moisture is also expected to push north into the Upper Mississippi Valley by the weekend. In general, subtle differences in how this system evolves over the coming days will play a roll in how much precipitation we see across the area this weekend. Precipitation chances look to peak late Friday into Saturday but continue off and on through the weekend into Monday. Expect these to be tailored a bit more as details come more into focus. Temperatures through this period will remain mild/slightly above normal in the 60s.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1212 PM CDT Mon Oct 26 2026

VFR conditions are likely throughout much of the period outside of any shower activity. Overall the CAMs have the highest probabilities for showers across portions of southeast MN and north-central WI tonight. As a result, have included a prob30 for showers later this evening at KRST. Otherwise, some MVFR cigs cannot be ruled out as well at times throughout the TAF period (20-40% in the recent HREF), however the highest probabilities (40-50%) would be at KRST close to 18z Tuesday. Winds will begin the TAF period from the east at around 5-10 kts but will gradually increase and switch directions to the south throughout the TAF period.

CLIMATE

Issued at 1244 AM CDT Mon Oct 26 2026

Record or near record temperatures Wednesday (Record/Forecast):

La Crosse, WI

Date High Temperature Warm Low Temperature ----- --------------- --------------- 10/28 75F (1945) / 73F 57F (1881) / 56F

Rochester, MN

Date High Temperature Warm Low Temperature ----- --------------- --------------- 10/28 73F (2024) / 71F 54F (1989) / 54F

ARX WATCHES/WARNINGS/ADVISORIES

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