textproduct: La Crosse

KEY MESSAGES

- Medium-High confidence (60-80%) in narrow 2" to 4" band of snow from southeast Minnesota into far northeast Iowa and parts of southwest Wisconsin through today. Initial, lighter snowfall band grazes northeast Iowa counties early this morning as subsequent, increased snowfall rates slightly farther north take shape through the morning and early afternoon into the evening.

- Sharp cutoff in snowfall expected north and south of narrow band. Confidence in extreme outliers of 6"+ within this narrow band remains low (30%) as 1" to 2" snowfall rates could transiently occur.

- Colder end to the weekend with warmer temperatures returning through early next week. Mixed precipitation chances increase Monday night through Tuesday morning.

UPDATE

Issued at 216 AM CST Sat Feb 28 2026

Lighter Radar Returns Through Northern Iowa:

Band of northwest-southeast radar returns seen from north- central Iowa through eastern into northern South Dakota are progressing east-southeast towards the forecast area. Eastern peripheral returns nearest to the forecast area approaching Floyd County as of 08Z haven't yet overcome lower level dry air with surface dewpoint depressions of 9-10 degrees through northern Iowa. Overall this aligns with previous forecasts for an initial, lighter, more southern reaching band through the early morning hours before subsequent enhanced low level frontogenesis takes shape through the late morning hours.

Observations & Subsequent Late Morning Snowfall Band On Track:

Muddled surface cyclonic rotation seen over western South Dakota into northern Nebraska driving subsequent enhanced low level frontogenesis and increased snowfall across the forecast area through the late morning into the early afternoon has been slow to take shape through the early morning hours. Although, decreased visibilities and snowfall reports have been observed through northern into eastern South Dakota. Upper level observations on GOES derived winds show the upper level jet streak that will provide required quasigeostrophic ascent poking through eastern Montana. Therefore, snowfall forecast timing mostly remains on track.

Hourly Forecast Model Updates & Location Confidence:

While the previous intermodel outlier HRRR forecast model has persisted the more southern track (00Z) of heavier snowfall in most recent runs (06Z, 07Z), in line with other high resolution models, more widespread snowfall to the north through central Wisconsin continues to be a questionable forecast detail to keep an eye on. While the previous (12Z, 18Z) northern track was mostly driven by a stronger surface low solution, weaker return flow will contend with very dry air to the north as current (830Z) surface dewpoint depressions are pushing 10 to 20 degrees. Given these observations, still expect and have continued messaging a tight gradient on /both/ the northern and southern edges of the band, but should the strong frontogenesis be enough to overcome the dry air with minimal moisture flux to work with, may warrant additional updates for some higher accumulations locally through central Wisconsin counties.

DISCUSSION

Issued at 1158 PM CST Fri Feb 27 2026

Snowfall Timing Today:

A narrow band of heavier snowfall progressing east through the forecast area through the morning hours and exiting this evening remains the main forecast concern. Early morning satellite, radar, and surface observations depict narrow band of lighter snowfall progressing east over the South Dakota - Minnesota border. This initial band expected to reach the local forecast area in southeast Minnesota and northeast Iowa early this morning. Subsequent heavier snowfall rates slightly farther north from southeast Minnesota into western and southwest Wisconsin will take shape through the morning hours. The responsible low level frontogenetical band is theoretically setting up over the North/South Dakota border this morning, slightly north of slightly ambiguous surface cyclonic rotation in western South Dakota.

Increased Confidence In Snowfall Band Location:

Fortunately, high resolution model consensus on exact location of frontogenesis and subsequent snowfall has improved over the last few runs. Previous outlying HRRR forecast model exhibited a significant shunt southwest between the 18Z and 00Z runs, advecting 0.1" of 6-hour QPF forecasted for this afternoon from the Interstate 94 corridor in Jackson County, Wisconsin to the Interstate 90 corridor in Olmsted County, Minnesota. Therefore, confidence has increased for location of higher snowfall band of 2" to 4" primarily in southeast Minnesota flirting far northeast Iowa into western and central Wisconsin.

Variability in exact location of narrow and relatively transient frontogenesis band providing higher snowfall rates causes some forecast challenges regarding sharp cutoff between snow and no snow. Furthermore, potential collocation with 5k - 10k ft DGZ thicknesses flirting slightly farther north continue forecast challenges for potential outlying extreme values within this band.

Otherwise, main forecast change was slight extension in preexisting Winter Weather Advisory in collaboration with neighboring forecast offices into the evening hours as high resolution models suggest lingering snowfall through this evening primarily in central Wisconsin before forcing fully exits east of the forecast area. While overall confidence has increased, an AFD update is likely this morning as the center of cyclonic flow further takes shape and subsequent snow bands set up. Upgrades to warnings may still be warranted given forecast challenge regarding potentially higher amounts.

Colder Sunday, Mixed Precipitation Potential Monday Night:

High pressure progresses through the forecast area on Sunday, keeping temperatures slightly below normal with daytime highs in the 20s area wide. While warmer temperatures are expected through the start of the week, stronger return flow will remain well south of the forecast area, keeping overall confidence lower (30-50%) with a quasi-zonal pattern and low level diffluence.

Largest change from previous forecasts is increased probabilities for mixed precipitation Monday night through Tuesday morning. A stronger solution to the mid level synoptic cyclone ejecting northeast through the Central Plains to start the week nearly doubled NBM PoPs over previous run, now grazing 80% across the southern reaches of the local forecast area. Unfortunately, ensemble (27.12Z) sounding plumes suggest all types of precipitation will be possible given warm, moist off low level airmass and the current overnight timing providing surface temperatures near to below freezing. Given the longer forecast hour and near freezing surface temperatures, many details in coming forecast packages will require ironing out as the system evolves.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 516 AM CST Sat Feb 28 2026

Both satellite and radar data is showing a slight southern shift in the snow band this morning. It still looks like both the TAF sites will still be impacted by accumulating snow. The snow will initially move into KRST around or after 28/15z and into KLSE around or after 28/17z. Snow amounts will likely range from 2 to 4 inches at KRST and and 2-3 inches at KLSE. Once the snow moves into the area ceilings and visibilities will become IFR/MVFR. These conditions will gradually improve late this afternoon and evening with VFR conditions expected overnight.

ARX WATCHES/WARNINGS/ADVISORIES

WI...Winter Weather Advisory until 9 PM CST this evening for WIZ032>034-041>044-053>055. MN...Winter Weather Advisory until 9 PM CST this evening for MNZ079- 086>088-094>096. IA...Winter Weather Advisory until 9 PM CST this evening for IAZ009>011.