FXUS65 KRIW 111750 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 1050 AM MST Mon Dec 11 2023 .DISCUSSION...This afternoon through Sunday Issued at 1034 AM MST Mon Dec 11 2023 Yesterdays shortwave has moved well away from the region, allowing pressure gradients to loosen up with winds remaining light and calm for today. A brief lull in weather will take place across central and eastern WY today. Elsewhere, northwesterly flow starts to weaken, reducing the upsloping induced snow across northwestern WY. Snowfall will gradually diminish across the Tetons and Gros Ventres, with little to no additional snow accumulation expected today. An upper level trough digs down across the Great Basin starting late this afternoon and evening. This will cause a shift in upper level flow to a more westerly/southwesterly direction. This flow will aid in producing scattered snow showers over parts of the Salt River and Wyoming Range, southern portions of the Tetons, and western slopes of the Wind River Mountains this evening and tonight. Lower elevation areas, such as the Green River Basin and northern Sweetwater County, may see brief periods of light snow during the afternoon and evening today lingering into the early morning Tuesday. Some models have shown the possibility for an isolated snow shower developing across parts of the Wind River Basin early Tuesday morning. While this cannot be ruled out, the majority of models indicate most of the precipitation to remain across southern portions of the CWA. Overall, trace accumulations are expected, with an isolated area of maybe an inch at most of accumulation. Impacts will remain minimal due to the lacking moisture keeping QPF values low and unfavorable atmospheric dynamics over our CWA. The upper level trough continues to dig farther south by late Tuesday, reaching the Four Corners region by early Wednesday morning. During this time, a closed low develops and moves eastward over the Southern Rockies and Southern Plains, keeping any impacts to our CWA too far south. The second half of the work week will see a large upper level ridge build in over much of the western CONUS. This ridge will bring back dry and fairly uneventful weather across the state, while aiding temperatures in returning to near or slightly above normal values. Beyond Friday the weather pattern looks to remain rather docile and uneventful, with little in terms of precipitation chances. Looking further ahead, current CPC guidances are indicating high possibilities of 60% to even 80% chances for above average temperatures and below average precipitation. So unless something major changes in the weather pattern, there is a good chance that the snow on the ground in the lower elevations will melt and will not see a white Christmas. So those of you who have wished for a brown Christmas, Enjoy! && .AVIATION...For the 18Z TAFS through 18Z Tuesday Issued at 1050 AM MST Mon Dec 11 2023 MVFR conditions at KJAC will continue for the first few hours of the TAF period, before improving to VFR. MVFR ceilings and VCFG will return around 09Z through 14Z. A band of light snow will occur across portions of southern Wyoming this afternoon, bringing in lower clouds and VCSH to KBPI, KPNA and KRKS. Increasing chances of snow will occur at KBPI/KPNA after 00Z, with MVFR conditions. This band of snow will lift northward through the night, briefly impacting KLND/KRIW and KCPR between 08Z and 12Z. Snow is expected to end by sunrise Tuesday morning, with a chance for lingering MVFR ceilings. Overall, snowfall rates are expected to be light, but MVFR conditions are expected. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .RIW WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...Dziewaltowski AVIATION...LaVoie