Alert archive / Wyoming / Winter Storm Warnings in 2021
Winter Storm Warning 1, NWS Riverton, WY
NWS Riverton, WY issued this winter storm warning at Jan 4, 2021, 2:53 AM MST for 4 counties in Wyoming. It took effect at Jan 4, 2021, 3:00 PM MST. It was in force for 21 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jan 4, 2021, 2:53 AM MST (09:53 UTC)
- In effect from
- Jan 4, 2021, 3:00 PM MST
- Expired
- Jan 5, 2021, 12:21 PM MST
- In force
- 21 hr
- Issued by
- NWS Riverton, WY
Counties Fremont County, WY, Lincoln County, WY, Sublette County, WY, Teton County, WY
The radar
The Riverton/Lander radar (KRIW), 120 km from the middle of the area, began a volume at 09:55 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Riverton, WY (KRIW), launched 00:00Z, 9.9 hours before the alert went out and 126 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1964 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 16 m²/s²
- 0-3 km storm-relative helicity
- 40 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
296 WWUS45 KRIW 040953 WSWRIW URGENT - WINTER WEATHER MESSAGE National Weather Service Riverton WY 253 AM MST Mon Jan 4 2021 ...A Winter Storm Warning and Winter Weather Advisories for far Western Wyoming late Monday Afternoon through Tuesday Afternoon... .Any snow showers through mid Monday afternoon are expected to have little accumulation. A storm system will impact western Wyoming late Monday afternoon and Monday night, before exiting the area Tuesday afternoon. Widespread significant snowfall over the west is likely with this storm system. WYZ012-050000- /O.UPG.KRIW.WS.A.0001.210104T2200Z-210105T2200Z/ /O.NEW.KRIW.WS.W.0001.210104T2200Z-210105T2200Z/ Teton and Gros Ventre Mountains- 253 AM MST Mon Jan 4 2021 ...WINTER STORM WARNING IN EFFECT FROM 3 PM THIS AFTERNOON TO 3 PM MST TUESDAY... * WHAT...Heavy snow expected. Total snow accumulations of 6 to 12 inches. 5 to 10 inches expected over the Gros Ventres and Togwotee Pass. * WHERE...Teton and Gros Ventre Mountains. * WHEN...From 3 PM this afternoon to 3 PM MST Tuesday. * IMPACTS...Travel could be very difficult over Teton and Togwotee mountain passes. Areas of blowing snow in combination with strong wind could result in near whiteout conditions. * ADDITIONAL DETAILS...Hikers and snowmobilers can easily become disoriented and lost. PRECAUTIONARY/PREPAREDNESS ACTIONS... Please monitor the Bridger-Teton Avalanche Center at JHAVALANCHE.ORG, if your plans include travel into the back country. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ WYZ001-050000- /O.UPG.KRIW.WS.A.0001.210104T2200Z-210105T2200Z/ /O.NEW.KRIW.WW.Y.0002.210104T2200Z-210105T2200Z/ Yellowstone National Park- Including the cities of Lake, Mammoth, and Old Faithful 253 AM MST Mon Jan 4 2021 ...WINTER WEATHER ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO 3 PM MST TUESDAY... * WHAT...Snow expected. Total snow accumulations of 4 to 8 inches, with locally higher amounts of 6 to 12 inches over southwestern portions of the park. * WHERE...Yellowstone National Park. * WHEN...From 3 PM this afternoon to 3 PM MST Tuesday. * IMPACTS...Travel could be difficult. * ADDITIONAL DETAILS...Hikers and snowmobilers could become disoriented and lost due to very poor visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ WYZ013-023-050000- /O.UPG.KRIW.WS.A.0001.210104T2200Z-210105T2200Z/ /O.NEW.KRIW.WW.Y.0002.210104T2200Z-210105T2200Z/ Jackson Hole-Star Valley- Including the cities of Jackson, Afton, Alpine, Star Valley Ranch, and Thayne 253 AM MST Mon Jan 4 2021 ...WINTER WEATHER ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO 3 PM MST TUESDAY... * WHAT...Snow expected. Total snow accumulations of 3 to 5 inches. * WHERE...Jackson Hole and Star Valley. * WHEN...From 3 PM this afternoon to 3 PM MST Tuesday. * IMPACTS...Travel could be difficult from snow packed roadways. The hazardous conditions could impact the morning and evening commute. * ADDITIONAL DETAILS...Hikers and snowmobilers could become disoriented and lost due to very poor visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... Please monitor the Bridger-Teton Avalanche Center at JHAVALANCHE.ORG, if your plans include travel into the back country. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ WYZ014-024-050000- /O.UPG.KRIW.WS.A.0001.210104T2200Z-210105T2200Z/ /O.NEW.KRIW.WW.Y.0002.210104T2200Z-210105T2200Z/ Wind River Mountains West-Salt River and Wyoming Ranges- 253 AM MST Mon Jan 4 2021 ...WINTER WEATHER ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO 3 PM MST TUESDAY... * WHAT...Snow expected. Total snow accumulations of 4 to 8 inches. Winds gusting as high as 35 mph. * WHERE...Wind River Mountains West and Salt River and Wyoming Ranges. * WHEN...From 3 PM this afternoon to 3 PM MST Tuesday. * IMPACTS...Travel could be difficult. Areas of blowing snow, in combination with heavier snow, could lead to near whiteout conditions in the mountains. * ADDITIONAL DETAILS...Hikers and snowmobilers could become disoriented and lost due to very poor visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... Please monitor the Bridger-Teton Avalanche Center at JHAVALANCHE.ORG, if your plans include travel into the back country. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ WYZ025-050000- /O.UPG.KRIW.WS.A.0001.210104T2200Z-210105T2200Z/ /O.NEW.KRIW.WW.Y.0002.210104T2200Z-210105T2200Z/ Upper Green River Basin Foothills- Including the city of Pinedale 253 AM MST Mon Jan 4 2021 ...WINTER WEATHER ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO 3 PM MST TUESDAY... * WHAT...Snow expected. Total snow accumulations of 2 to 4 inches. The heavier accumulations will occur near Bondurant and Hoback Junction. * WHERE...Upper Green River Basin Foothills. * WHEN...From 3 PM this afternoon to 3 PM MST Tuesday. * IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact the morning or evening commute. * ADDITIONAL DETAILS...Hikers and snowmobilers could become disoriented and lost due to very poor visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ For more information from the National Weather Service visit http://weather.gov/riw
3 follow-up statements
469 WWUS45 KRIW 042111 WSWRIW URGENT - WINTER WEATHER MESSAGE National Weather Service Riverton WY 211 PM MST Mon Jan 4 2021 ...A Winter Storm Warning and Winter Weather Advisories Posted for far Western Wyoming through Tuesday Afternoon... .Snow will become widespread across western Wyoming by early Monday evening. The snow will continue overnight before diminishing through the morning hours Tuesday and ending in the early afternoon. Most mountain locations will see snowfall totals exceed six inches. WYZ012-051300- /O.CON.KRIW.WS.W.0001.210104T2200Z-210105T2200Z/ Teton and Gros Ventre Mountains- 211 PM MST Mon Jan 4 2021 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 3 PM MST TUESDAY... * WHAT...Snow...heavy at times. Total snow accumulations of 7 to 14 inches, with totals of 5 to 10 inches in the Gros Ventre Range and over Togwotee Pass. Ridgetop and exposed areas could see winds of 25 to 40 mph. * WHERE...Teton and Gros Ventre Mountains. * WHEN...Monday Evening until 3 PM MST Tuesday. * IMPACTS...Travel could be very difficult over Teton and Togwotee mountain passes. Areas of blowing snow in combination with strong wind could result in near whiteout conditions. * ADDITIONAL DETAILS...Backcountry skiers and snowmobilers can easily become disoriented and lost. PRECAUTIONARY/PREPAREDNESS ACTIONS... Please monitor the Bridger-Teton Avalanche Center at JHAVALANCHE.ORG, if your plans include travel into the backcountry. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ WYZ001-051300- /O.CON.KRIW.WW.Y.0002.210104T2200Z-210105T2200Z/ Yellowstone National Park- Including the cities of Lake, Mammoth, and Old Faithful 211 PM MST Mon Jan 4 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 3 PM MST TUESDAY... * WHAT...Total snow accumulations of 4 to 8 inches, with locally higher amounts of 6 to 12 inches over the southwest portion of the park. Snowfall of 2 to 4 inches is expected from Mammoth to the Lamar Valley. * WHERE...Yellowstone National Park. * WHEN...Monday Evening until 3 PM MST Tuesday. * IMPACTS...Travel could be difficult. * ADDITIONAL DETAILS...Snowmobilers could become disoriented and lost due to very poor visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... Check on the latest conditions before departing and inform someone of your intended travel plans. && $$ WYZ013-023-051300- /O.CON.KRIW.WW.Y.0002.210104T2200Z-210105T2200Z/ Jackson Hole-Star Valley- Including the cities of Jackson, Afton, Alpine, Star Valley Ranch, and Thayne 211 PM MST Mon Jan 4 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 3 PM MST TUESDAY... * WHAT...Total snow accumulations of 3 to 5 inches. Local totals around 6 inches possible near Moose and Alpine. * WHERE...Jackson Hole and Star Valley. * WHEN...Monday Evening until 3 PM MST Tuesday. * IMPACTS...Travel could be difficult from snow packed roadways. The hazardous conditions could impact the Tuesday morning commute. * ADDITIONAL DETAILS...Snowmobilers could become disoriented and lost due to very poor visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... Please monitor the Bridger-Teton Avalanche Center at JHAVALANCHE.ORG, if your plans include travel into the backcountry. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ WYZ014-024-051300- /O.CON.KRIW.WW.Y.0002.210104T2200Z-210105T2200Z/ Wind River Mountains West-Salt River and Wyoming Ranges- 211 PM MST Mon Jan 4 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 3 PM MST TUESDAY... * WHAT...Total snow accumulations of 4 to 8 inches. Winds gusting as high as 35 mph. * WHERE...Wind River Mountains West and Salt River and Wyoming Ranges. * WHEN...Monday Evening until 3 PM MST Tuesday. * IMPACTS...Areas of blowing snow, in combination with heavier snow, could lead to near whiteout conditions in the mountains. * ADDITIONAL DETAILS...Backcountry skiers and snowmobilers could become disoriented and lost due to very poor visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... Please monitor the Bridger-Teton Avalanche Center at JHAVALANCHE.ORG, if your plans include travel into the backcountry. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ WYZ025-051300- /O.CON.KRIW.WW.Y.0002.210104T2200Z-210105T2200Z/ Upper Green River Basin Foothills- Including the city of Pinedale 211 PM MST Mon Jan 4 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 3 PM MST TUESDAY... * WHAT...Snow will increase Monday evening and continue overnight with total accumulations of 2 to 4 inches. Heavier snowfall of 4 to 6 inches will occur near Bondurant. * WHERE...Upper Green River Basin Foothills. * WHEN...Monday Evening until 3 PM MST Tuesday. * IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact the Tuesday morning commute. * ADDITIONAL DETAILS...Snowmobilers could become disoriented and lost due to very poor visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ For more information from the National Weather Service visit http://weather.gov/riw
041 WWUS45 KRIW 050754 WSWRIW URGENT - WINTER WEATHER MESSAGE National Weather Service Riverton WY 1254 AM MST Tue Jan 5 2021 ...A Winter Storm Warning and Winter Weather Advisories continue for far Western Wyoming through Tuesday Afternoon... .Snow will continue this morning, before diminishing through the morning hours and ending in the early afternoon. Most mountain locations will see snowfall totals exceed six inches. WYZ012-052200- /O.CON.KRIW.WS.W.0001.000000T0000Z-210105T2200Z/ Teton and Gros Ventre Mountains- 1254 AM MST Tue Jan 5 2021 ...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 3 PM MST THIS AFTERNOON... * WHAT...Snow...heavy at times. Total snow accumulations of 7 to 14 inches, with totals of 5 to 10 inches in the Gros Ventre Range and over Togwotee Pass. Ridgetop and exposed areas could see winds of 25 to 40 mph. * WHERE...Teton and Gros Ventre Mountains. * WHEN...Until 3 PM MST Tuesday. * IMPACTS...Travel could be very difficult over Teton and Togwotee mountain passes. Areas of blowing snow in combination with strong wind could result in near whiteout conditions. * ADDITIONAL DETAILS...Backcountry skiers and snowmobilers can easily become disoriented and lost. PRECAUTIONARY/PREPAREDNESS ACTIONS... Please monitor the Bridger-Teton Avalanche Center at JHAVALANCHE.ORG, if your plans include travel into the backcountry. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ WYZ001-052200- /O.CON.KRIW.WW.Y.0002.000000T0000Z-210105T2200Z/ Yellowstone National Park- Including the cities of Lake, Mammoth, and Old Faithful 1254 AM MST Tue Jan 5 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 3 PM MST THIS AFTERNOON... * WHAT...Total snow accumulations of 4 to 8 inches, with locally higher amounts of 6 to 12 inches over the southwest portion of the park. Snowfall of 2 to 4 inches is expected from Mammoth to the Lamar Valley. * WHERE...Yellowstone National Park. * WHEN...Until 3 PM MST Tuesday. * IMPACTS...Travel could be difficult. * ADDITIONAL DETAILS...Snowmobilers could become disoriented and lost due to very poor visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... Check on the latest conditions before departing and inform someone of your intended travel plans. && $$ WYZ013-023-052200- /O.CON.KRIW.WW.Y.0002.000000T0000Z-210105T2200Z/ Jackson Hole-Star Valley- Including the cities of Jackson, Afton, Alpine, Star Valley Ranch, and Thayne 1254 AM MST Tue Jan 5 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 3 PM MST THIS AFTERNOON... * WHAT...Total snow accumulations of 3 to 5 inches. Local totals around 6 inches possible near Moose and Alpine. * WHERE...Jackson Hole and Star Valley. * WHEN...Until 3 PM MST Tuesday. * IMPACTS...Travel could be difficult from snow packed roadways. The hazardous conditions could impact the Tuesday morning commute. * ADDITIONAL DETAILS...Snowmobilers could become disoriented and lost due to very poor visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... Please monitor the Bridger-Teton Avalanche Center at JHAVALANCHE.ORG, if your plans include travel into the backcountry. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ WYZ014-024-052200- /O.CON.KRIW.WW.Y.0002.000000T0000Z-210105T2200Z/ Wind River Mountains West-Salt River and Wyoming Ranges- 1254 AM MST Tue Jan 5 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 3 PM MST THIS AFTERNOON... * WHAT...Total snow accumulations of 4 to 8 inches. Winds gusting as high as 35 mph. * WHERE...Wind River Mountains West and Salt River and Wyoming Ranges. * WHEN...Until 3 PM MST Tuesday. * IMPACTS...Areas of blowing snow, in combination with heavier snow, could lead to near whiteout conditions in the mountains. * ADDITIONAL DETAILS...Backcountry skiers and snowmobilers could become disoriented and lost due to very poor visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... Please monitor the Bridger-Teton Avalanche Center at JHAVALANCHE.ORG, if your plans include travel into the backcountry. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ WYZ025-052200- /O.CON.KRIW.WW.Y.0002.000000T0000Z-210105T2200Z/ Upper Green River Basin Foothills- Including the city of Pinedale 1254 AM MST Tue Jan 5 2021 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 3 PM MST THIS AFTERNOON... * WHAT...Snow. Total accumulations of 2 to 4 inches. Heavier snowfall of 4 to 6 inches will occur near Bondurant. * WHERE...Upper Green River Basin Foothills. * WHEN...Until 3 PM MST Tuesday. * IMPACTS...Plan on slippery road conditions. The hazardous conditions could impact the Tuesday morning commute. * ADDITIONAL DETAILS...Snowmobilers could become disoriented and lost due to very poor visibility. PRECAUTIONARY/PREPAREDNESS ACTIONS... Slow down and use caution while traveling. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1. && $$ For more information from the National Weather Service visit http://weather.gov/riw
738 WWUS45 KRIW 051921 WSWRIW URGENT - WINTER WEATHER MESSAGE National Weather Service Riverton WY 1221 PM MST Tue Jan 5 2021 ...Accumulating Snow Has Ended Across Far West Wyoming... .The quick-hitting storm responsible for the overnight and Tuesday morning snowfall has departed east bringing an end to accumulating snowfall in far west Wyoming. WYZ012-052030- /O.CAN.KRIW.WS.W.0001.000000T0000Z-210105T2200Z/ Teton and Gros Ventre Mountains- 1221 PM MST Tue Jan 5 2021 ...WINTER STORM WARNING IS CANCELLED... The winter storm that brought 6 to 12 inches of snow to most locations has departed east. Therefore, the winter storm warning has been cancelled. Flurries will continue through much of this afternoon, but the accumulating snow has ended. $$ WYZ001-013-014-023>025-052030- /O.CAN.KRIW.WW.Y.0002.000000T0000Z-210105T2200Z/ Yellowstone National Park-Jackson Hole-Wind River Mountains West- 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 1221 PM MST Tue Jan 5 2021 ...WINTER WEATHER ADVISORY IS CANCELLED... The winter storm that brought snow to the western mountains and valleys has departed east. Therefore, the winter weather advisory has been cancelled. Flurries will continue in the mountains through much of this afternoon. However, the accumulating snow has ended. $$ For more information from the National Weather Service visit http://weather.gov/riw
The office that day
Everything else NWS Riverton, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 4, 2:53 AM MST | Winter Weather Advisory | RIW | Fremont, Lincoln, Park, Sublette, Teton | 33 hr |
Nearby
Winter Storm Warnings in Wyoming, 2021Every winter storm warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.