National Weather Service Riverton WY 1227 PM MST Mon Dec 30 2019 ...Winter storm will impact western Wyoming New Year`s Day... .A strong weather system will move across northwest Wyoming on New Year`s Day, bringing areas of heavy snowfall to western mountain ranges and nearby valleys. The heaviest snowfall will occur during the morning hours Wednesday, but will continue into Wednesday night. Yellowstone National Park-Teton and Gros Ventre Mountains- Jackson Hole-Star Valley-Salt River and Wyoming Ranges- Upper Green River Basin Foothills- Including the cities of Lake, Mammoth, Old Faithful, Jackson, Afton, Alpine, Star Valley Ranch, Thayne, and Pinedale 1227 PM MST Mon Dec 30 2019 ...WINTER STORM WATCH REMAINS IN EFFECT FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING... * WHAT...Heavy snow possible. Total snow accumulations 4 to 6 inches in the valleys. 8 to 16 inches in the mountains. Gusty winds at higher elevations could produce blowing snow. * WHERE...Portions of northwest and west central Wyoming. * WHEN...From Tuesday evening through Wednesday evening. * IMPACTS...Travel could be very difficult. The hazardous conditions will impact travel on New Year`s Day.