textproduct: La Crosse

KEY MESSAGES

- The first of three weather systems in the 7 day forecast impacts the region this afternoon into Wednesday morning. Main concerns will be snow/wintry mix (1-3 inches of snow, a glaze of ice), mainly north of I-90 and a low risk for hail across far southwest Wisconsin this afternoon.

- The second clipper system tracks over the area Thursday night into Friday morning. The bulk of the snow looks to stay north of I-94, but strong winds accompany this storm and may increase the impacts from even this light snow.

- The third, and likely highest impact, weather system lurks for late Saturday into Sunday, Confidence is high that this storm will bring a swath of 6+ inches of snow, it is just a matter of where across the Upper Midwest.

- Our stretch of spring warm fades into the rear-view mirror as cooler weather settles in for the remainder of the week and the weekend. A shot of winter temperatures is on tap for early next week, but looks brief.

DISCUSSION

Issued at 150 PM CDT Tue Mar 10 2026

This Afternoon: Hail Threat in Far SW Wisconsin

Forecast soundings and hodographs over far southwestern WI late this afternoon and evening (22-04Z) within the SPC Marginal Risk do support storms capable of hail around 1-2" with MUCAPE values of 500-1250 J/kg rooted just below the freezing level and elongated hodographs under -10C keeping the hail and rain core separated. That all being said, the straight hodographs favor storm splitters and the slab isentropic ascent could result in mass convective initiation with many storms fighting over limited inflow. If a couple of storm remain dominant, the hail threat will increase.

Tonight- Wednesday Morning: Wintry Mix/Accumulating Snow

Isentropic ascent over western WI steadily increases through the afternoon as an upstream trough amplifies over the Rockies. Fighting a mid-level dry slot, this lift is not realized as snow until it reaches north of Highway 29 tonight, falling as a somewhat narrow band of snow. Increasing low level saturation under this elevated warm front could lead to a period of freezing drizzle for areas north of I-90 in WI later this evening, but such a risk hinges on how fast temperatures cool after sunset. With highs having reached into the 40s and clouds increasing this evening, it will be a matter of 1-3 degrees playing a huge role in whether any drizzle freezes upon contact. Latent heat release from the drizzle may also keep the liquid from freezing if temperatures hang right around the 32 degree mark. While confidence in the freezing drizzle is not overly high at 40-60%, have issued a winter weather advisory to cover the possible threat, which will need to be evaluated as we go through the night.

Snow wraps southward on the backside of the deformation zone Wednesday morning with the short-range guidance coming in stronger on the strength of the attendant frontogenesis band. This has resulted in an increase in the snowfall amounts along and north of I-90 during the morning commute with 1-2" now the most likely scenario within this band.

Thursday Night - Friday Morning: Storm #2, Stronger Winds

A potent clipper wave digs across North Dakota and into northern Wisconsin late Thursday and Thursday night, departing by mid-morning Friday. Any locations south of the surface low see sufficient WAA to keep the attendant isentropic lift precipitation Thursday night falling as rain, with a sharp transition to snow along and north of the surface low track. The medium range solutions are in general good agreement in the the track of the low through differ more on the strength of the low by 5-8 mb. Could certainly see the need for a winter weather advisory north of the surface low track, locally favored north of WI Highway 29.

Strong northwesterly winds race southward in the wake of the trailing cold front, it's just a matter of how strong. There are some outlier solutions (5-10% of the distribution) that have winds at the top of the mixed layer pushing 50-60 kts, which could result in gusts over 50 mph if conditions line up appropriately. The impacts from any lingering light snow could be amplified quickly by these winds, but such mesoscale details will be hammered out in the next day or two.

Late Saturday/Sunday: Heavy Snow Band, But Where?

What may be our most impactful system of our 5 day winter storm trifecta remains on target for late Saturday into Sunday. A classic setup featuring a Front Range low lifting through the mid to lower Missouri River Valley and into the southern Great Lakes will play out during this time. The big question revolves around where the surface baroclinic zone sets up in the wake of our Thu night/Friday clipper. The north to south position of this boundary plays directly into whether this storm takes a northern track through MN/WI or a southern track through IA/IL. Our local forecast area lies in the cross hairs of this solution envelope, so confidence is high that somewhere in the forecast area will see impacts, it is just a matter of where.

The snow band itself looks to be rather impressive in nature, featuring a deepening surface low, favorable upper level kinematics, and aided by mesoscale forcing and ample Gulf moisture. The ingredients are coming together for snow amounts in the 6-12+" range. The reason for why the composite ensemble probabilities for 6-12 inches are only in the 10-30% range is due to placement, not intensity differences. This is certainly the storm system to watch as we move closer to the weekend.

Cooling Temperatures

Temperatures more typical of mid-March continue for the rest of the week and the weekend under predominantly northwest flow. Stronger CAA trailing our weekend system sends temperatures plummeting back to values more typical of early February. Highs on Monday only reach into the 20s with lows for Sun/Mon nights in the single digits--locales that see the fresh snow likely seeing lows fall below zero. This cold snap looks to only last a few days with highs rebounding back to near average through the rest of the week.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 624 PM CDT Tue Mar 10 2026

A cold front will move southeast through the area tonight. Scattered showers will be seen at KLSE this evening. In the wake of this front, IFR and MVFR ceilings will move into the area. Toward sunrise, a band of snow will produce MVFR visibilities. Snowfall amounts will be around an inch at both TAF sites.

ARX WATCHES/WARNINGS/ADVISORIES

WI...Winter Weather Advisory until 1 PM CDT Wednesday for WIZ017. Winter Weather Advisory from 11 PM this evening to 1 PM CDT Wednesday for WIZ029-034-042>044. MN...None. IA...None.