Area Forecast Discussion
Issued by NWS La Crosse, WI
Issued by NWS La Crosse, WI
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751 FXUS63 KARX 252009 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 309 PM CDT Wed Sep 25 2024 .KEY MESSAGES... - Trending drier through the weekend. Highs in the 70s to low 80s are forecast for the end of September, with signal for a potential cool down sometime early next week. && .DISCUSSION... Issued at 309 PM CDT Wed Sep 25 2024 No significant changes as a fairly quiet forecast remains on track. Clear skies, light low level flow, and longer nights will keep valley/river valley fog the main forecast concern in the short term. Have continued to mention valley fog for tonight/Wed morning and will continue to watch the subtle details for further potential and day to day impacts through the rest of the week. Otherwise, ensemble solutions look to be in better agreement on the overall pattern as a closed upper level low settles generally over the Mid-South region and Helene moves inland and eventually gets absorbed by the low. As has been noted with the past couple of forecasts, there has been a trend towards a drier forecast heading into the weekend, with highest probabilities in both the GEFS and ECMWF remaining just southeast of the forecast area. Have noted a handful of ECMWF and GEFS ensemble members hinting towards low probabilities (<30%) reaching towards far southwestern WI late in the weekend, so will continue to monitor trends over the next couple of days. Overall though, have maintained the drier forecast. Otherwise, forecast high temperatures remain in the 70s to around/low 80s. Heading into early next week model guidance shows an upper level trough and associated cold front moving through the region. Still a bit of spread between ensemble solutions in regards to precipitation potential and temperatures. However, there does appear to be signal for a cooling trend back down to more normal/below normal temperatures. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 107 PM CDT Wed Sep 25 2024 VFR conditions will prevail at both RST and LSE through the afternoon under high pressure. A field of FEW-SCT cumulus has developed across much of the region, generally around 4000ft. This deck may vary BKN at times, especially south of I-90, but is expected to dissipate this evening. Valley fog is expected to impact LSE again late tonight into Thursday morning as high pressure, clear skies, and weak winds continue to influence the area. Currently thinking that fog will begin to restrict visibilities to LIFR conditions around 26.10z although there may be drops in visibility in the hour or two before. Have gone with a 1/2SM visibility for now, but visibility of 1/4SM does appear possible again tonight. Fog should dissipate by late Thursday morning with VFR conditions again Thursday afternoon. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ DISCUSSION...EMS AVIATION...Falkinham