textproduct: La Crosse

KEY MESSAGES

- Clipper system brings periods of accumulating snow this afternoon through Saturday morning. While most locations in southeast MN and northeast IA will see under 2", portions of west-central and northern WI are expected to see 2-4" of snow through Saturday morning. - Blowing snow will be possible on Friday west of the Mississippi River with increasing wind gusts of 30 to 40 mph and snow showers. This may lead to localized visibility reductions on Friday afternoon.

- Light snow lingers Saturday and Sunday. Cannot totally rule out additional hazard from snow showers, but chances appear lower compared to Friday.

- Seasonably cold Saturday night through Monday night. Wind chills well below zero each morning, in particular Monday morning.

DISCUSSION

Issued at 321 AM CST Thu Jan 15 2026

Today - Tonight: Snow Moves in this Afternoon and Continues Overnight across Western Wisconsin

The stage is set for our winter system to move through the area later this afternoon as an upper-level ridge is sliding its way into the area that will enable some warm advection to push into the region. As this occurs, a shortwave quick on its heels will push into northern WI into the evening hours with a sfc low positioned to its north. Overall, these separate forcing mechanisms being displaced will result in various segments of this event, all of which pose some degree of impact. This afternoon, the hi-res CAMs bring in a band of light to moderate snow during the afternoon through the region associated with the aforementioned warm advection which will be our first round of accumulating snow with this system. Some question remains as to how much snow will occur with this initial warm advection as there is a notable dry layer in the HRRR/RAP soundings that any forcing would need to overcome and saturate before we could get snow production. In any case, the 15.00z HREF has respectable probabilities (30-60% chance) for amounts around 0.5", however anymore would likely be a stretch. Either way, this would be making its way through just towards the evening commute so some travel impacts would certainly be possible.

As this first round of snow departs, the weakening forcing results in a loss of saturation and ice in the dendritic growth zone across several of the CAMs soundings which would suggest the possibility for freezing drizzle to enter the picture during the evening hours, mostly south of I-94. Overall, this has been a consistent signal for a least a brief period of freezing drizzle to occur over the past 24 hours during the evening. In any case, impacts with this are unclear as the duration on the order of a couple of hours at the most prior to stronger forcing and cooler temperatures aloft switching p-types back to snow.

As we head later into the evening and into the overnight, the upper- level trough regime begins to center itself overhead accompanied with the surface low moving into north-central WI. Whats important here is the exact location of where this surface low positions itself late in the evening and overnight will be critical for how snowfall amounts will manifest in west-central and northern Wisconsin. Both the recent 15.06z RAP/HRRR really develop a small but mighty deformation region on the western flank of this low pressure center. In this scenario the RAP/HRRR has a narrow band of 4-6"+ with the stronger forcing in norther WI. Other scenarios for the overnight hours would keep the surface low pressure center further north and limit snow accumulations to some degree in the local area. Regardless, given the longer duration of the accumulation of snow, have opted to withhold any winter weather headline issuances as probabilities for 3 inches or greater within the 15.00z HREF still remain on the lower-end (30-50%) in north-central Wisconsin with current forecast amounts in the 1-3" range by 6am on Friday. That being said, if this low confidence and further south solution with a stronger surface low manifests, winter weather headlines would very likely be needed.

Friday: Blustery with Additional Snow Showers, Blowing Snow West of Mississippi River

By Friday morning, the aforementioned surface low and associated trough will begin to shift east providing a brief lull in precipitation, especially west of the Mississippi River. However, with flow beginning to shift northwesterly, increasing cold air advection and a tighter surface pressure gradient with the departing low, expecting winds to increase for the late morning and afternoon on Friday. As we head into the afternoon, a surface cold front sweeps through the area bringing some snow showers along with it. West of the Mississippi River, probabilities (60-90% chance) for wind gusts over 30 mph increasing sharply for the afternoon. As a result, blowing snow from both any recently fallen snow and snow showers will be a possibility with the 15.00z HREF having medium probabilities (30-60%) for more susceptible areas to see 1/2-mile vsby reductions or lower due to blowing snow during this period. Pretty unlikely we see true snow squall conditions with weaker instability as opposed to further west where the CAMs show more pronounced HCR-type snow showers. Additionally, flash freeze seems to be less of a concern at this point with probabilities in the HREF favoring below freezing temperatures (over 90% chance) throughout the day on Friday.

Lingering light snow Saturday and Sunday

Additional impulses in the northwesterly flow aloft look to eject downstream during the day Saturday, Saturday night, and again Sunday. Given lack of robust moist advection and frontogenetic enhancement to lift seen in most 15.00z models, current thinking is that snowfall rates and thus snow totals will be very light during these periods. Path for impacts would then focus on potential for snow showers and concomitant hazardous visibility reductions. Some progged soundings suggest boundary layer lapse rates will approach 9 C/km but with an overall reduction in moisture compared to the potential snow shower setup west of the Mississippi on Friday, probability for impacts is lower.

Seasonably cold Saturday night into at least Monday night

Passage of Friday's cold front will lead to, well, much colder temperatures Saturday night into at least Monday night, with each of these night having a 25-95% chance for values to drop below 0 depending on location. While none of these nights truly stands out from the perspective of potential radiational cooling due to lingering clouds from each of the upper impulses described above and less than optimal placement of the surface high and associated light winds, any break in the clouds should send temperatures dropping quickly. As for wind chill, worst night appears to be Sunday night into Monday morning as a decent pressure gradient looks to remain in place per 15.00z GFS/CMC and 14.12z EC, with the continued breeze potentially pushing wind chills below -20. Still plenty of details to shake out but will need to keep an eye over the coming days.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 502 AM CST Thu Jan 15 2026

VFR conditions this morning will give way to MVFR/IFR conditions during the afternoon as a band of light to moderate snow will progress through the region. Visibilities within this band will likely range between 2-4SM at times, perhaps under 2SM given that the 15.00z HREF has moderate probabilities for this (40-70% chance). Behind this band of snow, vsbys will improve but a brief period of freezing drizzle cannot be ruled out as saturation is lost aloft. This would likely be short-lived as we likely transition back to snow later into the evening and overnight with continued MVFR to IFR cigs towards 12z Friday. Winds will begin the TAF period light but quickly increase to around 10-15 kts for the afternoon. Winds will likely further increase west of the Mississippi River overnight to around 15-20 kts with gusts of 25-30 kts possible from the west- northwest.

ARX WATCHES/WARNINGS/ADVISORIES

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