Area Forecast Discussion
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
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416 FXUS65 KRIW 110142 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 642 PM MST Wed Dec 10 2025 .KEY MESSAGES... - Light snow showers linger overnight across Yellowstone and the Bighorns ending before sunrise Thursday morning. - High Wind Warnings remain in effect across southern WY where periodic gusts of 50 to 60 mph or more will be possible overnight, to include the Wind River Basing through midnight. - Mild, dry, and breezy conditions prevail across much of the Cowboy State through the upcoming weekend. && .UPDATE... Issued at 1233 PM MST Wed Dec 10 2025 Not much to add in terms of the short term forecast. The bulk of the precipitation across western WY has come to an end as of this afternoon. As a result of this, Winter Weather Advisories and Winter Storm Warnings across western WY have been cancelled early. A Winter Weather Advisory is still in effect across the western Bighorns due to some additional light snow accumulation of 1 to 3 inches through the afternoon. Otherwise, the High Wind Warning over southern Lincoln County has been cancelled. This is the result of lesser chances for winds of 50 mph or more. Gusty winds are still forecast but currently only ranging from 25 to 35 mph with periodic gusts around 40 to 45 mph. Besides a few changes in highlights the forecast remains mainly unchanged with well above normal temperatures persisting across the area through the weekend. Precipitation chances continue to be nearly non existent across much of the state with the one exception being western WY. Looking ahead, this pattern is expected to prevail through much of next week with a possible shift by the second half of the week. && .DISCUSSION... Issued at 218 AM MST Wed Dec 10 2025 The broad ridge across the western US continues to impact the overall lack of any semblance of a winter season so far across Wyoming, and does not look to improve this outlook for at least the next week. The current tap of moisture off the Pacific has been able to produce snowfall for the western mountains, but the warm lower valley temps keeps any precip as rainfall. A passing wave to the north will continue produce another 3 to 6 inches of snowfall for the western mountains, but the western ridge will build slightly this afternoon, pushing the moisture tap farther north, ending precip by this evening. The passing wave and cold front will keep the local gradient tight, resulting in strong and gusty winds across southern WY. A High Wind Warning remains in effect as gusts could still reach 60mph, but the frequency could be lower this afternoon. Temperatures remain particularly warm, with highs in the 40s and 50s for lower elevations, running about 5 degrees under record levels. Another cold front passes by to the north in Montana Thursday through Saturday. The moisture and energy will just clip far northern WY Thursday night into Friday morning, bringing another quick round of snowfall to the YNP, the Absarokas and the Bighorns, with minimal to no snowfall expected from the Tetons southward. The only other area of concern would be northern Johnson County, which could get a brief push of colder temperatures Friday, and some brief snowfall and gusty northwest winds could bring brief travel hazards Friday night along I-90. For the remainder of the region, the ridge will keep the warm temperatures in place through the weekend, with highs stuck in the 40s and 50s. This is troublesome for anyone that actually wants winter to arrive, especially local outdoor hockey teams that still don`t have hockey rinks for practice! && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 410 PM MST Wed Dec 10 2025 Dry and VFR flight conditions are forecast to persist the entire TAF period with clouds gradually clearing after sunrise on Thursday. Gusty winds persist at most terminals a majority of the TAF period, with KCPR and KRKS being the gustiest. The exceptions are KRIW, KLND, KBPI, and KWRL where winds are forecast to be 13kts or less. However, occasional gusts around 20 kts cannot be ruled out at these terminals (30% chance). 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... High Wind Warning until 5 AM MST Thursday for WYZ019-020-022- 028>030. && $$ UPDATE...Dziewaltowski DISCUSSION...Straub AVIATION...Gerhardt