textproduct: La Crosse

KEY MESSAGES

- Dry through Sunday night with above-normal temperatures.

- Rain chances from Monday afternoon through Tuesday...and then a gradual transition to rain and snow on Tuesday night...and snow Wednesday.

- Much colder on Thanksgiving with wind chills as low as the single digits.

DISCUSSION

Issued at 1234 PM CST Fri Nov 21 2025

Weekend

A weak cold front will move southeast through the area on Saturday afternoon and evening. With the soundings showing very little moisture with this system, kept the forecast dry. With the air mass in the wake of this system being of Pacific origin, there will be little temperature difference. High temperatures will range from the mid-40 to around 50 along and north of Interstate 94, and in the lower and mid-50s elsewhere for both days.

Monday through Wednesday

A shortwave trough will eject out of the southwest US and then move northeast through the Upper Mississippi River Valley and Great Lakes. There are 2 general camps on how this will occur. The first is that it will be rather progressive and move quickly northeast through the area. This currently comprises of 78% of the Grand Ensemble members. The second camp has this wave phasing with the northern stream. This results in a much stronger system (including a closed 500 mb and surface low) and deformation band of precipitation. This cluster comprises mainly of GEFS members and a total of 22% of the Grand Ensemble.

Thanksgiving

All of members are in general agreement that the area will be seeing cold air advection in the wake of the ejecting shortwave trough. Less than a quarter (22%) of the Grand Ensemble has some lingering light snow showers over the area. High temperatures will range from the mid-20s to mid-30s. Low temperatures on Thanksgiving morning will range from the mid-teens to lower 20s with wind chills in the single digits.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 556 PM CST Fri Nov 21 2025

The primary aviation forecast challenge over the next 24hrs remains the potential for valley fog at KLSE overnight into Saturday morning. Confidence remains low in this scenario as there's still uncertainty regarding how clear skies will be overnight. If skies are sufficiently clear, fog will likely begin to develop given light and variable low level winds. However, if fog does develop, it's not expected to last long past 11z-12z as an increased southwesterly low level wind field moves into the region. Have opted not to include fog mentions into the KLSE TAF, but remains something to keep a close eye on overnight.

Apart from the potential valley fog, VFR conditions are expected through the TAF period. Winds will be light and variable overnight, becoming southwesterly on Saturday. The aforementioned increased low level wind field should lead to surface gusts of 15-25kts through the day Saturday, strongest west of the Mississippi River.

ARX WATCHES/WARNINGS/ADVISORIES

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