textproduct: La Crosse

KEY MESSAGES

- Storms capable of producing heavy rain spreading east- northeast through the forecast this afternoon mostly raise river flooding concerns along flashier rivers in northeast Iowa and western Wisconsin. Low probability (<15%) for severe storms this evening and tonight.

- Freezing rain in central Wisconsin locally limited to eastern half of counties given tight near to below freezing surface temperature gradient.

- Mostly dry start to next week, precipitation chances return by mid next week.

DISCUSSION

Issued at 1259 PM CDT Fri Apr 3 2026

Ongoing Afternooon-Evening Storms:

Storms seen spreading northeast on radar imagery become widespread by early evening. While a weakening trend has been observed as storms push north, small, pea-sized hail has been observed locally in northeast Iowa. Similar is expected through the evening hours until eventual cyclogenesis along the low level baroclinic boundary advects a deepening low northeast towards the forecast area. While the accompanying tightening of the baroclinic boundary solidifies the east wind across the northern half of the forecast area, perpetuating the local weakening force field, a slight jaunt north in the boundary tonight and subsequent enhanced forcing along the accompanying cold front spreads storm chances slightly farther north primarily across the southern half of the forecast area tonight. Overall local concern will be heavy rainfall causing river flooding along flashier rivers; see Hydrology section below for further details.

Storm Chances Tonight:

Limited instability in high resolution soundings keep overall local storm threat low, although a quick progression to linear mode along the accompanying cold front creates concern for damaging winds given the fast motion. Main concern in far southern counties from northeast Iowa into southwest Wisconsin. While large hail can't be ruled out (5%), small hail accompanying strongest storms will be more likely hazard.

Freezing Rain Locally In Central Wisconsin Tonight:

Freezing rain concerns in central Wisconsin return tonight as precipitation chances push north through the afternoon/evening. Current afternoon observations a couple degrees above freezing expected to cool near and below freezing as the baroclinic boundary tightens, increasing east winds and CAA. Accumulations expected to be constrained to the eastern half of local counties given tight below freezing temperature gradient. Furthermore, ice accumulations expected to be limited to grassy and elevated surfaces with highest amounts of 0.1" to 0.2" expected.

Flurry Chances Saturday:

As the low shifts over the Great Lakes Saturday, initial light rain chances switch to light snow and flurry chances through the afternoon while shifting east-southeast through the forecast area. Current high resolution forecast soundings suggest transient low level instability from stronger low level CAA causing short bursts of visibility reductions within these stronger flurries. Overall accumulations expected to be minimal.

Mostly Dry Start to New Week:

By the time we get to 12Z Sunday, our area will be in northwest flow aloft on the backside of the departing troughing regime that rotates over Eastern Canada. With the moisture largely worked over from the departing system, conditions should remain dry through the day on Sunday. Moving into Monday, a shortwave impulse will work its way through the northwest flow aloft around the Great Lakes which could create some light snow showers across North Central Wisconsin. The main limiting factor will be a significant lack of moisture as we will not have had any appreciable moisture return by then. Any accumulations, if there are any in our area, should be very light and not impactful.

As the troughing regime finally slides off to the east, a surface high will swing into the region during the day on Tuesday. This should keep the forecast dry and cool through then with high temperatures near to slightly below normal in the upper 30s to mid 40s.

Precipitation Chances Increase by Middle of Next Week:

Activity starts to ramp up by mid-week as flow becomes more zonal aloft. A shortwave trough and corresponding surface low are expected to drop out of British Columbia and slide across the Northern CONUS through Thursday/Friday. As the trough and low pressure center swing northeast back into Canada by the weekend, a trailing cold front is progged to stall somewhere across the region. With abundant moisture expected to pool along and south of the frontal boundary, widespread continued precipitation chances look increasingly likely in the zone around the boundary. Because precipitation totals will depend heavily on the available moisture and hence the location of the boundary, will hold off on giving any reasonable deterministic QPF totals at this time. Overall, current forecasts don't show anomalously high pWats to suggest significant heavy rainfall and flooding concerns, even as PoPs hold in the chance to likely range from Wednesday evening onwards. Current NBM probabilities of 72 hour precipitation totals exceeding 1 inch from Thursday through Saturday sit in the 50-70% range which supports the current notion that a healthy rainfall is expected for the late week timeframe. Temperatures during this period look to be in the 50s to 60s, supporting a fully rain event.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 642 PM CDT Fri Apr 3 2026

Showers and scattered storms will continue for the TAF sites throughout the evening. As storms move through the area, visibilities will become briefly IFR/MVFR. Throughout the TAF period, ceilings will be LIFR/IFR.

HYDROLOGY

Issued at 1240 PM CDT Fri Apr 3 2026

Heavy rainfall accompanying storms spreading northeast through the local forecast area early this afternoon will cover the forecast area by the evening hours. As high resolution guidance envelops the entirety of the forecast, higher QPF values compared to previous forecasts suggest 1.5"+ over flooding susceptible rivers in Wisconsin (e.g., Kickapoo, Black, Yellow) and Iowa (e.g., Turkey). Therefore, collaborated higher QPF forecast with WPC and NCRFC for additional river forecasts at 18Z. Given these rainfall values aligned with 80th+ percentile QPF in previous forecasts, expect additional impacts to action stage or minor flooding at susceptible river sites.

Overall impacts will depend on exact location of band of higher values and subsequent drainage into flooding susceptible rivers. While low probability (<10%), moderate flooding cannot be ruled out should training storms repeat heavy rainfall over the same sites.

ARX WATCHES/WARNINGS/ADVISORIES

WI...Winter Weather Advisory until 7 AM CDT Saturday for WIZ017-029. MN...None. IA...None.