WWUS45 KRIW 180914 WSWRIW URGENT - WINTER WEATHER MESSAGE National Weather Service Riverton WY 314 AM MDT Mon May 18 2026 WYZ015-190000- /O.CON.KRIW.WS.W.0005.000000T0000Z-260519T0000Z/ Wind River Mountains East- 314 AM MDT Mon May 18 2026 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Heavy snow expected. Additional snow accumulations between 5 and 9 inches, with locally higher amounts at the highest elevations. Winds gusting as high as 60 mph. * WHERE...Wind River Mountains East. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel could be very difficult. The hazardous conditions could impact the Monday morning commute, including over South Pass. PRECAUTIONARY/PREPAREDNESS ACTIONS... If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ018-190000- /O.CON.KRIW.WS.W.0005.000000T0000Z-260519T0000Z/ Lander Foothills- Including the cities of Lander 314 AM MDT Mon May 18 2026 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Snow expected. Additional snow accumulations between 5 and 8 inches, with higher amounts near Sinks Canyon Park. * WHERE...Lander Foothills. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel could be difficult. The hazardous conditions could impact the Monday morning commute. Heavy snow could break tree limbs as many trees have leafed out. PRECAUTIONARY/PREPAREDNESS ACTIONS... If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ019-190000- /O.CON.KRIW.WS.W.0005.000000T0000Z-260519T0000Z/ Green Mountains and Rattlesnake Range- Including the cities of Jeffrey City 314 AM MDT Mon May 18 2026 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Heavy snow possible. Additional snow accumulations between 6 and 12 inches possible with locally higher amounts up to 15 inches. Winds gusting as high as 55 mph. * WHERE...Green Mountains and Rattlesnake Range. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel will be difficult. The hazardous conditions will impact the Monday morning commute. PRECAUTIONARY/PREPAREDNESS ACTIONS... If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ020-190000- /O.CON.KRIW.WS.W.0005.000000T0000Z-260519T0000Z/ Natrona County Lower Elevations- Including the cities of Casper 314 AM MDT Mon May 18 2026 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Heavy snow expected. Total snow accumulations between 3 and 6 inches. Areas of higher amounts up to 8 inches between Hiland and Casper and the south side of Casper. Winds gusting as high as 40 mph. * WHERE...Natrona County Lower Elevations. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel will be difficult, especially along US Highway 20/26 between Hiland and Casper. The hazardous conditions will impact the Monday morning commute. Heavy snow could break tree limbs as many trees have leafed out. PRECAUTIONARY/PREPAREDNESS ACTIONS... If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ022-190000- /O.CON.KRIW.WS.W.0005.000000T0000Z-260519T0000Z/ Casper Mountain- 314 AM MDT Mon May 18 2026 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Heavy snow possible. Additional snow accumulations between 6 and 12 inches possible. Winds could gust as high as 40 mph. * WHERE...Casper Mountain. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel could be very difficult. Areas of blowing snow could significantly reduce visibility. The hazardous conditions could impact the Monday morning commute. Heavy snow could break tree limbs as many trees have leafed out. PRECAUTIONARY/PREPAREDNESS ACTIONS... If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ030-190000- /O.CON.KRIW.WS.W.0005.000000T0000Z-260519T0000Z/ East Sweetwater County- Including the cities of Wamsutter 314 AM MDT Mon May 18 2026 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Heavy snow expected. Additional snow accumulations between 4 and 8 inches. Lower amounts up to 2 inches in the Rock Springs area. Winds gusting as high as 60 mph. * WHERE...East Sweetwater County. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel will be very difficult, especially along Interstate 80 due to the crosswind component. The hazardous conditions will impact the Monday morning commute. PRECAUTIONARY/PREPAREDNESS ACTIONS... If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ002-007>009-190000- /O.CON.KRIW.WW.Y.0019.000000T0000Z-260519T0000Z/ Absaroka Mountains-Owl Creek and Bridger Mountains-Bighorn Mountains West-Bighorn Mountains Southeast- 314 AM MDT Mon May 18 2026 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Snow expected. Additional snow accumulations up to 6 inches, with the higher amounts expected over southern end of the Bighorn Mountains. Winds gusting as high as 50 mph. * WHERE...Owl Creek and Bridger Mountains, Bighorn Mountains Southeast, Bighorn Mountains West, and Absaroka Mountains. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel could be difficult, especially over mountain passes such as Powder River Pass. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ003-005-190000- /O.CON.KRIW.WW.Y.0019.000000T0000Z-260519T0000Z/ Cody Foothills-Southwest Bighorn Basin- Including the cities of Cody, Clark, Thermopolis, and Meeteetse 314 AM MDT Mon May 18 2026 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Snow expected. Total snow accumulations up to 2 inches. Winds gusting as high as 50 mph. * WHERE...Southwest Bighorn Basin and Cody Foothills. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel could be difficult due to a combination of snow and wind. The hazardous conditions could impact the Monday morning commute. * ADDITIONAL DETAILS...There is potential for a steep gradient in snow totals along the mountains, with snow totals quickly going from around 1 inch to 4 inches or more. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ010-011-190000- /O.CON.KRIW.WW.Y.0019.000000T0000Z-260519T0000Z/ Northeast Johnson County-Southeast Johnson County- Including the cities of Buffalo and Kaycee 314 AM MDT Mon May 18 2026 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Snow expected. Total snow accumulations up to 2 inches. Winds gusting as high as 35 mph. * WHERE...Northeast Johnson County and Southeast Johnson County. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel could be difficult due to a combination of wind and blowing snow. The hazardous conditions could impact the Monday morning commute. * ADDITIONAL DETAILS...Greatest snow totals will occur along the mountains and further southwards towards Kaycee. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ014-190000- /O.CON.KRIW.WW.Y.0019.000000T0000Z-260519T0000Z/ Wind River Mountains West- 314 AM MDT Mon May 18 2026 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Snow expected. Additional snow accumulations between 4 and 8 inches. Winds gusting as high as 60 mph. * WHERE...Wind River Mountains West. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel could be difficult, especially along South Pass. The hazardous conditions could impact the Monday morning commute. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ016-017-190000- /O.CON.KRIW.WW.Y.0019.000000T0000Z-260519T0000Z/ Upper Wind River Basin-Wind River Basin- Including the cities of Riverton, Dubois, and Shoshoni 314 AM MDT Mon May 18 2026 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Snow expected. Additional snow accumulations between 1 and 4 inches, with locally higher amounts are possible around Hudson and Fort Washakie. Winds gusting as high as 45 mph. * WHERE...Upper Wind River Basin and Wind River Basin. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel could be difficult due to a combination of snow and wind. The hazardous conditions could impact the Monday morning commute. Where heavy snow occurs, it is possible for tree limbs to break, as many trees have leafed out. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ026-190000- /O.CON.KRIW.WW.Y.0019.000000T0000Z-260519T0000Z/ Upper Green River Basin- Including the cities of Big Piney, Farson, and La Barge 314 AM MDT Mon May 18 2026 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Snow expected. Total snow accumulations 1 to 3 inches. Winds gusting as high as 45 mph. * WHERE...Upper Green River Basin. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel could be difficult due to a combination of wind and falling snow. The hazardous conditions could impact the Monday morning commute. * ADDITIONAL DETAILS...Greatest impacts will be further south, towards Farson. Here, winds and snow totals will be greatest. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ027-190000- /O.CON.KRIW.WW.Y.0019.000000T0000Z-260519T0000Z/ South Lincoln County- Including the cities of Kemmerer and Cokeville 314 AM MDT Mon May 18 2026 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Snow expected. Additional snow accumulations between 1 and 3 inches. Winds gusting as high as 40 mph. * WHERE...South Lincoln County. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel could be difficult. The hazardous conditions could impact the Monday morning commute. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ WYZ028-029-190000- /O.CON.KRIW.WW.Y.0019.000000T0000Z-260519T0000Z/ Rock Springs and Green River-Flaming Gorge- Including the cities of Rock Springs and Green River 314 AM MDT Mon May 18 2026 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM MDT THIS EVENING... * WHAT...Snow expected. Additional snow accumulations between 2 and 5 inches. Winds gusting as high as 55 mph. * WHERE...Flaming Gorge and Rock Springs and Green River. * WHEN...Until 6 PM MDT this evening. * IMPACTS...Travel could be difficult, especially along Interstate 80. The hazardous conditions could impact the Monday morning commute. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. For graphical depictions of the snowfall forecast, including the official NWS forecast, high end amounts, and low end amounts, visit https://weather.gov/riw/winter . For winter road conditions from the Wyoming Department of Transportation, visit https://wyoroad.info . && $$ For more information from the National Weather Service, visit https://weather.gov/riw/ . TL