FXUS63 KARX 201017 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 517 AM CDT Fri Mar 20 2026 .KEY MESSAGES... - Warm into Saturday with daytime highs from the 50s to 60s for Friday increasing into the 60s and upper 70s for some on Saturday. See Climate section below for local climate sites records and current forecast. - Light precipitation chances (10-25%) Saturday night through Sunday likely will require an increase in coming forecast packages. - More seasonable temperatures through next week with low confidence (10%) in precipitation potential middle and late week. && .DISCUSSION... Issued at 1037 PM CDT Thu Mar 19 2026 Potential Record Warmth Into The Weekend: Warming temperatures into the early weekend, from building heights in a west coast upper level ridge advecting east through the Central CONUS on GOES water vapor imagery loops this evening, continues to be the main forecast detail. The overachieving today (Thursday) temperatures not only provided ample snow melt to drop local albedo but also exemplified a seasonal NBM cool temperature bias in the current regime. Therefore, in collaboration with neighboring forecast offices, have bumped daytime high temperatures up a few degrees using 75th+ percentile NBM blends. While this seemingly breaks the mold compared to model guidance, observations and trends support this forecast adjustment. Resultant highs locally from the mid 50s to upper 60s Friday and 60s to upper 70s Saturday. Therefore, record daytime warmth looking more possible on Saturday, see climate section below for local climate site records compared to current forecasts. Low Precipitation Confidence This Weekend: The ridge will break through the late weekend, allowing a cold frontal boundary to sag south through the Upper Mississippi River Valley. While intraensemble trends exhibit persistent agreement over their recent respective runs, interensemble consensus has weakened for precipitation chances Saturday night into Sunday. The lowest probabilities (10-40% 0.01" QPF/24hr) in the GEFS (19.18Z), decreasing in previous runs, due to a stronger, later solution for weakening of the high pressure centered over the Desert Southwest, ironically disagrees most strongly with its AI counterpart (GEFS AI 19.18Z) which paints a widespread 60-80% for similar 0.01" QPF/24hrs Saturday night through Sunday. While the EPS (19.18Z) slightly differs in probabilities (50-90%) from its AI counterpart's (ECMWF AIFS 19.18Z) probabilities (40-80%) for 0.01" QPF in 24 hours, interintraensemble trends have both been on the increase over recent runs. Regardless of the confusing dichotomy, besides the GEFS (18.19Z), all aforementioned long term global ensembles (GEFSAI, EPS, ECMWFAIFS) now flirt limited probabilities (10-30%) for higher rainfall amounts (0.1" QPF/24hrs) in the headwaters of Wisconsin. Current forecast package and WPC collaboration keeps 5- 25% PoPs across the forecast area in a limited window Saturday night. More Seasonable Temperatures Through The New Week: As the synoptic high pressure locks in a more seasonable airmass locally through the start of the week, precipitation chances return through the middle and later next week as the baroclinic boundary strewn near the forecast area gets its act together and northwest flow provides forcing for potential cyclogenesis. Current confidence keeps best forcing well north of the forecast area, passing filaments of increased moisture through the Upper Mississippi River Valley. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 516 AM CDT Fri Mar 20 2026 A cold front will move through the area overnight and Friday morning. This will only cause a wind shift from south to northwest today. the winds will then shift backto the south tonight. Otherwise, ceilings and visibilities will be VFR. && .CLIMATE... Issued at 1037 PM CDT Thu Mar 19 2026 Potential Record Warmth on Saturday, March 21st, 2026: Forecast / Record High Rochester, MN: 75 / 70 (1918) La Crosse, WI: 74 / 75 (2022) && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...JAR AVIATION...Boyne CLIMATE...JAR