textproduct: La Crosse

KEY MESSAGES

- One more mild day today with highs in the 40s south of I-94. Winds will increase by the afternoon and persist into Wednesday with periodic gusts to around 35 mph, mainly west of the Mississippi River.

- Accumulating snow is likely beginning Thursday afternoon and continue into Friday. Probabilities for snowfall amounts of 2 inches or greater are trending higher across the local area (50-90% chance).

- Below normal temperatures expected this weekend with highs likely in the single digits and teens.

DISCUSSION

Issued at 255 AM CST Tue Jan 13 2026

Today: One More Mild Day with Afternoon & Evening Rain/Snow Showers

We have got one more mild day in store for today as a weak shortwave exits to our east this morning. Still cannot rule out (10-20% chance) a brief period of freezing rain across portions of Taylor County over the next few hours this morning, however given the HRRR/RAP soundings really struggling with low-level saturation, this possibility of impacts from this is on the lower side. Otherwise, westerly flow during the daytime hours will allow our mild airmass to remain in place. Consequently, expecting highs to yet again reach into the 40s for much of the local area south of I-94. Winds will also increase by the afternoon as the combination of a tightening surface pressure gradient and momentum transfer of winds around 30 kts off the deck will allow for gusts of 25 to 35 mph this afternoon and evening. As we head into the evening and overnight, a cold frontal boundary will begin to push into the area which the CAMs suggest will instigate some isolated to scattered rain/snow showers with its passage. However, not expecting much impact from these at this time with low-level lapse rates not being all that steep.

Wednesday - Friday: Seasonably Cold with Accumulating Snow Likely Thursday Afternoon Through Friday

Wednesday will feature a noticeable change in temperatures as highs return to seasonable with median high temperatures in the NBM ranging from the upper teens to middle 20s and lows Wednesday night likely falling into the single digits for most of the local area. Additionally, winds will remain breezy during the morning and afternoon with the cold advection behind the aforementioned surface frontal passage. Consequently, the 13.00z HREF has respectable probabilities (40-70% chance) for wind gusts over 35 mph continuing into Wednesday. However, probabilities for gusts higher than this are quite low (under 20% chance). Regardless, will certainly make a cold day feel even colder for Wednesday.

The next system of focus moves into the region on Thursday in form of a pronounced shortwave troughing regime on Thursday afternoon. As this initial shortwave moves into the area, strong QG convergence will be the main forcing mechanism with this as the NAM/GFS do not show any overtly strong signal for frontogenesis with this feature. Consequently, expecting a period of light to moderate snow beginning Thursday evening and continuing into Friday. The key question with this, that has some variance in deterministic guidance, is if any additional subtle shortwave perturbations will move through the broader troughing regime into the local area. Currently, ensemble guidance generally favors this solution which would suggest keeping periods of snow going throughout the day on Friday.

As far as snowfall amounts are concerned, probabilities are fairly high (50-90% chance) in the grand ensemble (GEFS/EC/Canadian ensemble) for accumulations in excess of 2 inches across much of the local area with the highest probabilities (70-90%) near and north of I-90. This is assuming a snow to liquid ratio of around 15 to 1 which is NBM mean SLR for this event. The exact ceiling for snowfall amounts remains contingent on how the forcing mechanisms evolve, particularly into Friday. Confidence is very high that we will see a period of accumulating snow with the initial shortwave Thursday afternoon and into Friday morning. However, additional forcing mechanisms behind the initial shortwave passage will be key to determining how accumulating snow would trend later into the day on Friday. In any case, it is very likely we will see a period of accumulating snow beginning on Thursday afternoon and continuing into Friday. There are some increasing probabilities (20-50%) for slightly higher snowfall amounts in excess of 4 inches in the grand ensemble (GEFS/EC/Canadian ensemble) from Thursday afternoon through Friday night. However again, this would be contingent on how subsequent forcing mechanisms manifest within the broader troughing regime.

This Weekend: Below Normal Temperatures Likely with Some Snow Chances

By the time this weekend rolls around, cold advection with a surface cold front associated with the aforementioned shortwave will push through the area resulting in well below normal temperatures for the day on Saturday. Still some uncertainty with exactly how cold we get as deterministic and ensemble guidance has not yet resolved exactly where the core of this arctic airmass ends up. Consequently, the inter-quartile range for highs on both Saturday and Sunday ranges anywhere from the single digits above zero to around 20 for highs. Overnight lows during this period have a similar degree of variance with inter-quartile range of the NBM, ranging from the teens below zero to single digits above zero. So fairly high confidence that we will be below climatological normals for the weekend, questions just linger on exactly how cold.

As far as precipitation chances are concerned for the weekend, some post-frontal snow showers will be possible during the day on Saturday. This is generally as a result of the aforementioned low- level cold advection steepening low-level lapse rates along with the cyclonic flow in place within the northwesterly flow regime. Overall fairly strong probabilities (50-80%) in the grand ensemble (GEFS/EC/Canadian ensemble) for measurable snow on Saturday. However, probabilities for amounts of an inch or greater are low (10-20% chance). Given that we will be in northwest flow on Sunday and into early next week, will have to watch to see if we can get any shortwaves to progress into the region within the northwesterly flow. However, deterministic and ensemble guidance have low predictability on how any systems during that period would evolve at this point.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 445 AM CST Tue Jan 13 2026

VFR conditions are expected to continue through much of the morning with increasing winds into the early afternoon to around 15-20 kts. Winds gusts up to around 25-30 kts will be possible from this afternoon into Wednesday with highest gusts west of the Mississippi River in unsheltered locations. LLWS will continue to be a consideration at KLSE this morning, however by mid to late morning increasing wind gusts will reduce any LLWS concerns. VFR cigs this morning will give way to MVFR cigs this afternoon with the recent HREF having high probabilities (60-90% chance) for ceilings below 2000ft. These will likely persist through the overnight with some chance for improvement back to VFR towards 12z on Wednesday. A stray rain/snow shower will be possible (15-20% chance) later this afternoon and evening at KLSE however confidence was not high enough to include in this TAF issuance.

ARX WATCHES/WARNINGS/ADVISORIES

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