textproduct: La Crosse

KEY MESSAGES

- Our stretch of cold weather continues through the first half of the new week, with the coldest temperatures coming Monday night as lows crater into the teens. Temperatures rebound back to around normal for Thursday into next weekend.

- Several passing shots of light rain or snow showers this evening and Sunday, with Monday into Tuesday shaping up to be mostly dry.

- Widespread rain starting Tuesday night and continuing off and on through the end of the week. The general setup doesn't overly favor the excessive rainfall amounts we saw over the last few days, but could still affect river levels.

DISCUSSION

Issued at 149 PM CDT Sat Apr 4 2026

Tonight: Snow Showers Linger

Evening water vapor imagery shows a tightly wound cyclone tracking across north-cetnral Wisconsin and residual cyclonic flow lingering in its wake across the forecast area. The continued differential cold air advection through the boundary layer this evening should sustain some of the ongoing rain/snow showers past sunset, with the loss of daytime heating slowly resulting in a decrease in the areal coverage of these showers before midnight. Visibility reductions of 2-4 miles have been observed in some of the heaviest showers, but these have been transient in nature.

Sunday: Slightly Warmer, Rain Showers Late

A downslope-modified airmass advects off the High Plains and across the mid to lower Missouri River valley during the day on Sunday ahead of an approaching upper tropospheric shortwave trough. This airmass clips the forecast area, boosting high temperatures back closer to average (low to mid 50s). However, this warm spell will be short-lived as a cold front arrives in the late afternoon/evening, bringing with it scattered light rain showers, possibly mixing with snow into central Wisconsin if profiles can cool fast enough. There should be no impacts from this rain/snow on the ongoing flooding (rainfall of <0.10"), but sets the stage for a cold start to the week.

Precipitation Chances Increase Midweek Through Late Week:

Otherwise, a mostly dry start to the new week is expected, allowing area rivers to recover from 3"+ precipitation totals over the last 48 hours and ongoing river flooding in spots. Subsequent mixed precipitation chances reach the local forecast area Tuesday night as a Canadian Rocky Mountain Low phases along the International border, advecting an area of enhanced moisture within a tightening warm sector across the forecast area. Current confidence for local impacts initially remains minimal until later in the week as the quasi-zonal boundary gets abandoned on our southern doorstep. Subsequent moisture resurgences provide persistent precipitation chances and increasing instability through the end of the week. Current confidence for increased instability initially Thursday along and west of the Mississippi River Valley slowly shifts northeast through the Upper Midwest as the more tropical airmass wins out slowly over the Upper Mississippi River Valley Friday & Saturday.

Heavy rain concern given the synoptic setup will require close monitoring given current state of swollen to flooded rivers for much of the forecast area. Current LREF (04.00Z) confidence is low with 0.25" spread within members and little agreement in location between members.

Colder Temperatures To Start The Week:

An anomalously cold airmass glances the Upper Midwest through the start of the week with minimum percentile low level temperatures (SPC MPX RAOB climatology) Monday night. While resultant surface temperatures are expected to be 10+ degrees warmer than cold records at La Crosse, WI and Rochester, MN, apparent temperatures may dip into the single digits depending on wind speeds into the overnight.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 650 PM CDT Sat Apr 4 2026

A mix of low VFR to high MVFR ceilings can be found this evening across the area, with MVFR ceilings becoming more prevlant as we move towards 03-06Z. These ceilings look to break around sunrise Sunday with VFR conditions for many locales south of an EAU to ISW line for much of the day. A line of showers approaches in the mid to late afternoon on Sunday and could bring periods of MVFR to IFR conditions into Sunday evening and night. Winds remain out of the northwest through the period at 10-15kts, gusting to 20-30 kts overnight and 15-20kts for the day on Sunday.

HYDROLOGY

Issued at 236 PM CDT Sat Apr 4 2026

After widespread 1-3+ inches of rainfall fell across the region yesterday through early this morning, area rivers have seen increased flows, some of which have climbed into flood stage. The main basin of concern has been the Kickapoo River, where the heaviest axis of rain fell. As this is a notoriously flashy basin, it's not a huge surprise that it quickly jumped into Major Flood stage earlier this morning to nearly 20 ft. Fortunately, as quickly as it jumped up it has already come back down to below action stage early this afternoon (12.52 ft as of 2 pm). This jump to major flood stage lead to some road closures in Vernon/Monroe Counties around Ontario where many feeder streams come in to the Kickapoo. This wave of water is expected to work its way down the river over the coming day(s) with most other sites downstream expected to go into Minor Flood stage based on current forecasts. There are still some roads across Vernon County that are closed due to water over them from flooded creeks/rivers, especially in Chaseburg along the Coon Creek. Water is expected to gradually subside though impacts from debris left behind might linger.

Other rivers of concern are the Turkey River in Iowa, the Yellow River in Necedah, and the Black River at Black River Falls. All of these locations are currently seeing or expected to go into minor flood stage in the coming hours/days. While a few sprinkles/flurries will be possible both this afternoon and tomorrow afternoon, any additional QPF will be minimal to nil for most locations. The next significant chance for precipitation across the region doesn't look to come until mid- next week.

ARX WATCHES/WARNINGS/ADVISORIES

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