FXUS65 KRIW 181041 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 341 AM MST Sun Jan 18 2026 .KEY MESSAGES... - A weak weather system will bring gusty winds and a chance for light snow across the northern Bighorn Mountains and northern Johnson County this morning. - The remainder of western and central Wyoming remain mild and dry the rest of the weekend and most of the upcoming week. && .DISCUSSION... Issued at 123 AM MST Sun Jan 18 2026 The H5 ridge along the west coast is not going anywhere during the next few days, so the status quo continues across most of western and central Wyoming. Moisture content wrapping around the top of the ridge remains dry, so any systems passing through will have a hard time wringing out any precip. A weak shortwave is racing southward across the Plains this morning, with the tail edge just clipping along the edge of the Bighorn Range. Overnight webcams and road conditions show any precip that fell with this has been very light and dry, with minimal accumulation. Winds across Johnson County have been gusting 25 to 35 mph, with a few higher gusts. This has kept most light snow from accumulating, and would likely keep blowing the snow all the way to Nebraska... The ridge will keep the area in the milder temperatures through the rest of this week, with high temperatures varying between the 30s and 40s, depending on any gusty winds bringing downsloping. Another weak shortwave again sweeps by to the northeast Tuesday night, bringing another round of gusty winds and light snow mainly to the Bighorns and northern Johnson County. The western valleys are unlikely to see any significant west winds this week being closer under the ridge, so cold pools in the valleys will hold in place, keeping temps in the 20s and low 30s. Cautiously optimistic that the western ridge finally breaks down late this week, allowing a more significant weather system into northern Wyoming over the upcoming weekend. This may bring a considerable drop in temperatures and a better chance for snowfall for all mountain ranges through the weekend. && .AVIATION /12Z TAFS THROUGH 12Z MONDAY/... Issued at 335 AM MST Sun Jan 18 2026 West of the Divide...KBPI/KJAC/KPNA/KRKS Terminals. VFR conditions should prevail for all terminals. Wind will increase somewhat in the afternoon. There is around a 1 in 10 chance of a shower in vicinity of KRKS after 05Z Monday but not enough confidence to include in the TAFs. East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals. A cold front will move in from the north Sunday, bringing some gusty breezes and lower ceilings, with local MVFR conditions possible after 03Z tonight. There is little moisture with the front, so any snow showers would be confined to in and near the mountains as well as in vicinity of KBYG. We have added vicinity showers to KCOD and KLND where there is around a 1 in 5 chance of a shower, but enough confidence to prevail as precipitation would be showery and hard to pinpoint. 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...Straub AVIATION...Hattings