Mt. Lacrosse Snow Report

955 FXUS63 KARX 310655 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 155 AM CDT Mon Aug 31 2026 .KEY MESSAGES... - Low confidence (<25%) in storms today increases Tuesday and Wednesday night. - Above normal temperatures from the mid 80s to 90s expected through midweek. && .DISCUSSION... Issued at 146 AM CDT Mon Aug 31 2026 Warming Through The Week With Frequent Precipitation Chances: A cyclonically wrapping extratropical cyclone on upper level water vapor imagery loops slowly trudges east through the start of the new week, circumnavigating and exerting influence on a synoptic upper level ridge over the central CONUS, resulting in the local forecast area sandwiched in the accompanying confluence zone. Resultant periodic precipitation and storm chances frequent the local forecast area mostly during the nighttime hours through the start of the week. Storm Chances Today: Daily lowest local confidence (<25%) for storms Today can be attributed to high resolution soundings suggesting low level dry air causing a capping inversion. Learning from Sunday, when storms were able to initiate under similar model conditions as widespread sky cover throughout the daytime hours limited low level mixing, resulting in more moist lower levels than previously expected, and high based (8000`) storms accessing mid level instability. Therefore, have veered away from high resolution models for Today which again suggest copious mixing causing a strong, dry low level inversion. Degree of cooling/moistening of low level inversion will be determining factor in coverage and strength of storms through today. More boisterous solutions in previous RAP (30.21Z) and recent HRRR (31.00Z) raises local concerns for potentially severe storms in a very narrow temporal and spatial window within convergent zone along surface frontal boundary. Large hail and damaging winds would be the main threats should severe storms come to fruition. Storm Chances Through The Week: Confidence in storms increases through the start of the week, from Tuesday night as moisture-laden southwest low level flow advects northeast along a meager, lifting upper/mid level perturbation behind the exiting synoptic trough axis and again Wednesday night as a narrow corridor of higher storm/precipitation potential from a burbling low level theta e lobe along our southern periphery again advecting northeast. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1231 AM CDT Mon Aug 31 2026 With some cooling tops across parts of southeast Minnesota and northeast Iowa, kept the PROB30 for thunderstorm chances in the KLSE TAF through 31.10z. In addition, the nocturnal jet will produce low-level wind shear overnight at KLSE. As this jet veers toward sunrise (around 31.10z), the low level-wind shear will come to an end. With no cap showing up in the soundings on Monday and Monday evening, there will be some isolated to scattered showers and storms. However, location and timing is highly uncertain; thus, kept them out of the TAFS for now. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...JAR AVIATION...Boyne