textproduct: La Crosse

KEY MESSAGES

- Light snow tonight east of the Mississippi River (amounts mainly 1/2" or less) with a 2-3 hour period in which we could see light freezing drizzle Thursday morning.

- Another transient round of light snow/freezing drizzle clips western Wisconsin Thu night/Fri morning. Impacts are more difficult to nail down with the system being weaker and temperatures flirting with the freezing mark.

- Aside from a brief cooldown for the start of the weekend, temperatures beyond today are expected to be well above normal with highs in the 30s and possibly low 40s next week.

DISCUSSION

Issued at 110 PM CST Wed Feb 4 2026

Tonight/Thursday Morning: Light Snow, Morning Freezing Drizzle?

Over the course of the next 24 hours, a compact upper tropospheric shortwave carves out the eastern flank of longwave ridge that is anchored over the western CONUS. This wave drops into the western Great Lakes Thursday morning with a 130 kt jet streak providing ample kinematic lift along the nose of the jet in conjunction with a corridor of lower tropospheric isentropic ascent. While the overall moisture profiles are far from ideal, there is a 6-9 hour window at any given location that we could see precipitation, with the highest probabilities of seeing measurable precip east of the Mississippi River and especially along/northeast of I-94.

Snow will be the main p-type at the start after midnight and amounts will be around 1/2" or less, but the loss of ice at the tail end of the precipitation after sunrise opens a 2-3 hour window for freezing drizzle in the morning hours before the forcing and boundary layer moisture depart by midday. Given the short window of opportunity and drying moisture profiles during this time, confidence is not high in the degree of impacts from freezing drizzle. Any ice amounts will be light (a glaze at best), but could come during the morning commute and make untreated roads slick.

Thursday Night - Friday Morning: Light Wintry Mix Again

The upper level ridge builds slightly farther to the east during the day on Thursday before the next ripple cascades down its eastern flank Thursday night. With the overall pattern shifted slightly farther east, the main impacts from any precipitation should be confined closer to central WI, but there is a 20% chance that it could spread as far west as the Mississippi River. Once again, moisture profiles will straddle supporting snow versus freezing drizzle. Similar to tonight's system, the system will be transient and impacts limited in time and space. However, unlike tonight, temperatures will be warming overnight and continue warming above freezing by sunrise, further mitigating any impacts from freezing drizzle.

Weekend - Early Next Week: Warmer, Mostly Dry

The mean blocking longwave ridge that has been situated along the West Coast this week breaks down and slides eastward at the end of the week, transitioning more to a zonal/southwesterly pattern for the weekend and early next week. This synoptic shift will keep any Arctic air confined to the north, with the exception on one intrusion on Friday night/Saturday. As the ridge starts to flatten, a PV lobe rips southeastward across Manitoba and Ontario, dragging a pool of Arctic air with it. The coldest air remains to the north, but lows Saturday morning could fall below zero along and north of I-94 (30-50% chance). The surface ridge axis passes through Saturday morning and temperatures rebound through the afternoon, with highs on Sunday returning back to similar values that are forecast for the two days leading up to Saturday (mid to upper 30s on Thu/Fri of this week).

Looking ahead to next week, the overall pattern continues to feature either a zonal or southwesterly component, keeping the stretch of above average temperatures going for much, if not all, of the week. The region will reside along the northern periphery of the thermal ridge and thus there is a decent spread in the >35-45 degree high temperature probabilities from south to north through the forecast area. However, even the NBM 10th percentile high temperature grids areawide for the start of the week are above normal, a solid indication for the high confidence in seeing at least above normal temperatures, it is just a matter of how warm. Such things as cloud cover and the influence of our snow pack will start to come into play when answering that question and it remains too far out to nail down much more for specifics.

While the NBM forecast for the weekend and early next week has very low PoPs, there are several ripples in the pattern that could result in very light rain/snow Saturday night, Sunday, and Tuesday, but the strongest signal for impactful precipitation is around Wednesday and Thursday. The guidance is certainly quite diverse in the strength and track of this system, but at this time it represents the next shot of impactful weather to the Upper Midwest.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 544 PM CST Wed Feb 4 2026

MVFR to potentially IFR cigs are expected through the overnight as a weather disturbance moving in from the north brings in low-level moisture to the local area. As a result, probabilities (40-70%) increase for MVFR in the HREF/NBH this evening through the daytime hours on Thursday. Additionally, a period of IFR cigs seems plausible at KRST late this evening and into the overnight given the HRRR showing low saturation at around 1kft or less at times. Consequently, have introduced some IFR mention for a few hours during this period. Otherwise, will need to watch for some snow and/or freezing drizzle at KLSE overnight and into the morning hours as this system works its way through the area. However, confidence in impacts at the TAF site remain low at this point. Continued MVFR with occasional VFR is trending more likely in recent probabilistic guidance for the daytime hours on Thursday so have opted to maintained MVFR cigs for a longer duration.

ARX WATCHES/WARNINGS/ADVISORIES

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