Area Forecast Discussion
Issued by NWS La Crosse, WI
Issued by NWS La Crosse, WI
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276 FXUS63 KARX 201819 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 1219 PM CST Thu Nov 20 2025 .KEY MESSAGES... - Low stratus and patches of fog and drizzle continue through this afternoon. - Gradual warm up for the weekend with highs generally in the upper 40s to mid 50s. - Increased rain chances (50 to 75%) for Monday into Tuesday. Colder temperatures for the second half of next week. && .DISCUSSION... Issued at 1219 PM CST Thu Nov 20 2025 Today: Drizzle Deep low level saturation continues today with low stratus as well as some fog and drizzle at times. These conditions are expected to continue until a weak cold front pushes through the region later this afternoon into the early evening, helping to bring in drier air and lifting the cloud deck. With the low clouds in place for much of the day, have continued the trend of lowering high temperatures for today. High temperatures for day are now mostly in the 40s across the CWA. Friday-Sunday: Dry and Gradual Warm Up A split flow upper level pattern covers much of the northern Plains and Upper Midwest into early next week. A trough sets up to our north with a shortwave coming out of the souther Rockies. Guidance continues to show this system from the Rockies staying to our south with minimal rain chances (<15%) for our far southern counties. There is low chance that a shortwave comes far enough south on Saturday afternoon into Sunday that could bring some light rain showers to areas north of I-94, however only the deterministic ECMWF and 5% of EPS members show this solution occurring. The NAM does indicate some shower potential as there is a weak cold front that accompanies this wave. One thing inhibiting more guidance showing showers, is that based on NAM and GFS soundings at this time, there is quite a bit of dry air in the low levels. This wave may more than likely just increase cloud cover briefly. Outside of these low chances, a mostly dry weekend is in store. Temperatures for this weekend are looking quite pleasant for late November with highs generally in the upper 40s to low 50s. Sunday is expected to be the warmest day with highs mostly in the low to mid 50s. Monday-Thanksgiving: Increased Precipitation Chances Through Midweek, Cooler Temperatures Mid to Late Week The split level flow becomes interrupted on Monday evening as a low pressure system comes up from the southern Rockies. Previous forecasts had this system staying mainly south of the forecast area with only the EPS showing most of its members (70 to 80%) with measurable precipitation while the GEFS members hardly had any members (around 30%) with precipitation. Since yesterday, Ensemble and deterministic guidance has shifted this low further north into much of the Upper Midwest. Now 80 to 100% of both GEFS and EPS members have measurable precipitation. The latest LREF has a 30 to 40% chance for greater than 0.25" of rain to fall between Monday night and Tuesday evening. When looking at WPC cluster analysis. Each of the four clusters shows this low coming out of the Rockies and into the Upper Midwest, then getting absorbed into the parent longwave trough. The main differences, based on ensembles, is location and strength of this low. Despite this system occurring at night, rain is the likely precipitation type with temperatures mostly in the mid 30s to low 40s. After Tuesday, with northwest flow in place through the rest of the week, we could see some flurries on Wednesday and Thursday. In addition, with the pressure gradient appearing the way it is, could see some breezy conditions both days with gusts up to 25 mph. Once this low moves through, colder and drier air follows the longwave trough as it dips down into the northern CONUS. Temperatures at 850mb are currently ranging between -8 and -12C for the second half of next week. While both ensemble and deterministic guidance agrees that colder air moves down next week, the EPS and ECMWF are slightly warmer than the GFS and GEFS, indicating that the GEFS solution is deeper compared to the EPS solutions. Regardless, temperatures for Wednesday compared to Tuesday will be 10 to 15 degrees cooler with highs in the low to mid 30s. By Thanksgiving and heading into the weekend, we could see highs in the 20s to low 30s. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1200 PM CST Thu Nov 20 2025 LIFR/IFR conditions continue over the next few hours for much of the region, ahead of a cold front that will move through the region this afternoon. This cold front will shift the current south to southwesterly winds to the northwest. Behind the front, drier air will be ushered into the region which is expected to help improve conditions to Low MVFR/MVFR. Confidence is not overly high regarding when VFR conditions return as a solid MVFR stratus deck extends into the northern Great Plains behind the front. Currently thinking MVFR conditions should linger into at least the overnight hours for much of the region, but will be dependent on how much this low stratus deck dissipates this afternoon. Greater confidence in VFR conditions comes towards the end of the TAF period. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...Cecava AVIATION...Falkinham