textproduct: La Crosse

KEY MESSAGES

- Dangerous cold continues in the immediate term through midday today. After a relative respite midweek, anomalous cold returns Friday and through the weekend. At this time, the coldest morning is favored to occur Saturday. Headlines will likely be warranted.

- High confidence, particularly south of I-90 (95% chance), that another light snow event will occur Tuesday night with potential for a second round of snow Wednesday afternoon. Totals across both rounds combined may (30-50%) reach 3" south of I-90.

DISCUSSION

Issued at 331 AM CST Mon Jan 19 2026

Dangerous cold this morning and then again this weekend

Light snow has finally moved out of the area overnight but brisk winds remain as winds out of the northwest continue to gust to around 25-35 mph with sporadic gusts to 45 mph as of 07z. Despite a good amount of cloud cover, air temperatures are in the single digits above and below zero. Thus, dangerously cold wind chills are occurring with values generally in the -20 to -35 range. With a 30- 40 knot 850mb jet favored to remain over the area until around 18z, will keep the Cold Weather Advisory going until noon. After noon and into tonight, reducing winds should keep wind chills from falling back under 25 below zero even air temperatures remain around 0.

Next large scale upper low looks to churn southeast over Ontario Thursday night, ushering very cold air into the region. Morning lows will very likely be below zero Friday (65-95% per 19.01z NBM), Saturday (80-100%), and Sunday (75-95%) mornings. Lingering pressure gradient and a light breeze Friday morning may lead to wind chills of 25 below or lower. Saturday morning, the surface high building in the wake of the upper low may lead to air temperatures in the 15 below to 25 below range, opening the door for highly dangerous wind chills should any light breeze develop. Unfortunately, operational 19.00z runs of the GFS/EC place the center of the surface high in our CWA Saturday morning and 19.00z LREF grand ensemble does as well, suggesting this is a probable outcome. Will need to closely monitor over the coming days as widespread impacts would occur Friday night into Saturday morning should this come to pass.

Light snow likely Tuesday night, potential second round Wednesday afternoon

Broad agreement across 19.00z guidance that another clipper type system will eject out of Alberta Tuesday evening into Tuesday night. Given run to run consistency within operational NAM/GFS/EC/CMC runs and support in 19.00z ensembles, opted to increase PoPs above NBM values (from 10-70% to 40-95%). Compared to our last few clippers, this may have a bit more snow with it as, while moisture remains hard to come by, stronger forcing for ascent courtesy of a bit of 700/850mb frontogenesis may develop. Similar to the past weekend, progged soundings show a deep DGZ and an all light, fluffy snow event. Reflecting the potential for more accumulation, 19.07z NBM has a 10-30% chance to reach 3" south of I-90 Tuesday evening/night, which seems reasonable given quick hitting nature of the system. Wednesday afternoon, a quickly following disturbance out of Saskatchewan will likely (60%) bring additional light snow, pushing the chance to reach 3" closer to 30-50% south of I-90 across both events.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 527 AM CST Mon Jan 19 2026

Expect clouds in the 1500-2500 foot range for much of the next 24 hours with timing MVFR/VFR at a give time largely being determined by sky cover. Sky cover should tend to decrease with time and thus expect VFR to eventually become present across the region by late in the period. Otherwise, northwesterly gusts to around 25-30 knots continue early in the period with gusty winds continuing through 00z Tuesday.

ARX WATCHES/WARNINGS/ADVISORIES

WI...Cold Weather Advisory until noon CST today for WIZ017-029- 032>034-041>044-053>055-061. MN...Cold Weather Advisory until noon CST today for MNZ079-086>088- 094>096. IA...Cold Weather Advisory until noon CST today for IAZ008>011-018- 019-029-030.