textproduct: La Crosse

KEY MESSAGES

- Above normal temperatures from the mid 40s to low 50s expected for Friday.

- Confidence is increasing for a narrow band of snow to impact portions of our forecast area. Given how narrow the band is, uncertainty remains where exactly this snow band ends up and how much snow a given location will get.

- After a cooler weekend, temperatures warm back up into the 40s for next week.

DISCUSSION

Issued at 107 PM CST Thu Feb 26 2026

Today-Friday: Dry, Warming Up

Northwest flow aloft continues over the Upper Midwest as the area is under the southern periphery of a longwave trough. In the lower levels, southwest flow takes over allowing for good warm air advection to filter into the region. High temperatures today get into the upper 30s to low 40s, with locations that have minimal to no snowpack potentially getting into the mid 40s. Heading into Friday, the warm air advection continues. The pressure gradient tightens over the area as a low passes through northern Minnesota and southern Ontario. As a result, southwesterly winds increase during the late morning with sustained winds of 15 to 25 mph and gusts of 25 to 35 mph. These winds continue as a front pushes through the area during the afternoon shifting the winds to the northwest. The winds then diminish Friday night. With this strong low level flow and mean LREF 850mb temperatures between 2 and 7 degrees C, surface temperatures will get into the upper 40s to low 50s for most locations. Depending on how much we can mix, temperatures may be slightly warmer and the winds may be slightly stronger. Temperatures in the deeper snowpack may only get into the low to mid 40s.

Saturday: Narrow Band of Snow

After the cold front moves through on Friday, most of the remaining moisture gets pushed southward as drier air enters the area behind the front. Some residual moisture remains in place as a band of mid to low level frontogenesis moves through the northern Plains and into the Upper Midwest. Ensemble and deterministic data continue to get into better agreement on a snow band across these regions. There are still slight disagreements on the placement of this band and given that this is a frontogenetic band, it will be quite narrow, just a few counties wide, so location of this band may continue to wiggle over the next day or so. As far as amounts go, this mornings model runs have increased snow amounts slightly. There is better agreement amongst models of a narrow 1 to 3" band of snow, however there are some individual ensemble members that produce higher amounts. Looking at the higher percentiles of the NBM (75th and 90th) some of these totals are in the 3 to 5" range. Given the amount of forcing associated with this band and the DGZ depth of 2500 to 3000m, these higher snow totals may be possible. As a result, a Winter Weather Advisory may be needed once the location is narrowed down.

Sunday: Light Snow Possible

Winds shift more zonal for the beginning of next week. Another snow chance is possible on Sunday night into Monday as a low pressure system develops in the Central Plains. There is some disagreement on the location of this low as the GFS is further south towards southern Missouri while the ECMWF and CMC are more in northern Missouri. The GFS also keeps the northern periphery of this low dry with some mid level subsidence but the ECMWF has secondary frontogenesis band developing north of the low. This results in light snow for portions of northeast Iowa, southeast Minnesota and far southwestern Wisconsin. We shall see how this transpires over the next couple of days to see which track is favored.

Next Week: Warm Up and Precipitation Chances

By the time Monday arrives, the flow aloft shifts more west to southwest. This will aid in storm tracks coming out of the southwest for next week with more potential for low pressure systems to move through rather than little clipper systems. The first potential storm might be midweek as both the GFS and ECMWF and their ensembles favor a more active mid to end of next week. There are some lower precipitation chances for early next week across areas mostly south of I-90 as a shortwave passes through the region. With the southwest flow aloft temperatures will gradually warm up and by midweek highs look to get into the mid to upper 40s for most.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 552 PM CST Thu Feb 26 2026

Main aviation concern will be strengthening nocturnal low level jet causing temporary LLWS near day break before surface winds can mix and increase through Friday morning. Therefore, have included short bout of LLWS at KRST for Friday daybreak whilst slightly longer at KLSE given surface wind tendencies at both locations. Sufficient mixing through Friday will increase surface winds area wide providing low level turbulence instead of LLWS. Surface winds may remain increased through Friday night.

Narrow band of snowfall through Saturday morning will be subsequent, potentially more relatively widespread, aviation impacts. Current confidence places west-northwest to east- southeast oriented band over the forecast area through Saturday morning. Climatologically expect IFR visibilities where snow falls.

ARX WATCHES/WARNINGS/ADVISORIES

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