FXUS65 KRIW 271735 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 1135 AM MDT Mon Oct 27 2025 .KEY MESSAGES... - Valley rain and mountain snow will continue across the region today, with snow accumulations continuing above 8000 feet. Winter conditions will continue for most mountain passes through the day. - Gusty northwest winds return today, with widespread gusts above 30 mph expected. - Cold temperatures continue Tuesday before moderating through the rest of the week. && .DISCUSSION... Issued at 221 AM MDT Mon Oct 27 2025 The broad trough continues to sweep across the northern Rockies this morning. This is keeping the moisture feed off the Pacific well placed for lift along local mountain ranges. Models continue to show elevated lift aloft through the rest of the day, which will continue to aid in snow production. Peak times for the northwest mountains should be between now and around noon, with the focus shifting briefly east to the Bighorns this afternoon. Additional snowfall accumulations of 3 to 6 inches is expected before the system moves out tonight. Current warnings and advisories mesh well with the current timings, so will not need any adjustments here. As the system moves east this evening, a brief period of rain/snow mix will develop for Natrona and Johnson Counties, with snow accumulations up to a half inch possible. Winds will also come up across the state today, as the northwest flow aloft mixes down to the sfc. Widespread wind gusts above 30 mph are expected, except for the more shaded places across NW WY. The southern half of the state will see even higher gusts this afternoon, with frequent gusts 40 to 50 mph likely (>60%). High pressure builds in for Tuesday, with much colder temperatures. Highs will struggle to reach 40 degrees, before falling into the teens and low 20s Tuesday night. H5 ridging builds across the Rockies midweek, deflecting the next system into Montana. Right now it would only provide some high clouds during the day. Models differ on the next system which may pass through Friday night, with a wide range of strength and moisture available. Current trend is for a drier passage, with milder temperatures in the 50s and 60s remaining through the weekend. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1135 AM MDT Mon Oct 27 2025 West of the Divide...KBPI/KJAC/KPNA/KRKS Terminals One last wave of snow showers will move through the KJAC area at the start of the period. Occasional MVFR conditions will be expected at KJAC through 22Z as a result. IFR conditions are possible as well, but confidence in IFR is much lower (less than 20% chance) so have kept with MVFR for now. After 00Z, all terminals will see improving conditions and clearing skies. Winds also decrease by around 00Z with light winds, VFR conditions, and mostly clear skies prevailing through the rest of the period. The exception will be KJAC where midlevel cigs are likely to hold on through at least 15Z Tuesday. East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals Gusty winds persist at most terminals through the afternoon, but winds decrease at most sites around 00Z this evening. As the last of this latest weather system finally pushes out later today, KCPR could see some wrap-around moisture and thus shower chances through portions of the afternoon and evening. By 06Z, however, all sites will see VFR conditions, mostly light winds (less than 12kts) and clearing skies. These tranquil conditions will prevail through the rest of the period. 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... Winter Storm Warning until 6 PM MDT this evening for WYZ001- 012. Winter Weather Advisory until noon MDT today for WYZ002-014- 015-024. Winter Weather Advisory until 6 PM MDT this evening for WYZ008. && $$ DISCUSSION...Straub AVIATION...Hensley