968
WWUS45 KRIW 181846
WSWRIW
URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE RIVERTON WY
1246 PM MDT MON MAY 18 2026
WYZ016-017-182000-
/O.CAN.KRIW.WW.Y.0019.000000T0000Z-260519T0000Z/
UPPER WIND RIVER BASIN-WIND RIVER BASIN-
INCLUDING THE CITIES OF SHOSHONI, RIVERTON, AND DUBOIS
1246 PM MDT MON MAY 18 2026
..WINTER WEATHER ADVISORY IS CANCELLED
THE MAJORITY OF SNOW HAS ENDED. MINOR IMPACTS DUE TO WIND AND LIGHT
SNOW MAY CONTINUE THROUGH THE REST OF THE DAY, BUT CONDITIONS SHOULD
GRADUALLY IMPROVE.
WYZ015-190000-
/O.CON.KRIW.WS.W.0005.000000T0000Z-260519T0000Z/
WIND RIVER MOUNTAINS EAST-
1246 PM MDT MON MAY 18 2026
...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS
EVENING...
* WHAT...HEAVY SNOW. ADDITIONAL SNOW ACCUMULATIONS UP TO 2 INCHES,
WITH 4 TO 6 INCHES AT THE HIGHEST ELEVATIONS. WINDS GUSTING AS
HIGH AS 40 MPH.
* WHERE...WIND RIVER MOUNTAINS EAST.
* WHEN...UNTIL 6 PM MDT THIS EVENING.
* IMPACTS...TRAVEL WILL BE VERY DIFFICULT, ESPECIALLY 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
1246 PM MDT MON MAY 18 2026
...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS
EVENING...
* WHAT...SNOW EXPECTED. ADDITIONAL SNOW ACCUMULATIONS UP TO 2 INCHES.
* WHERE...LANDER FOOTHILLS.
* WHEN...UNTIL 6 PM MDT THIS EVENING.
* IMPACTS...TRAVEL COULD BE DIFFICULT. 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
1246 PM MDT MON MAY 18 2026
...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM MDT THIS
EVENING...
* WHAT...HEAVY SNOW. ADDITIONAL SNOW ACCUMULATIONS 1 TO 4 INCHES.
WINDS GUSTING AS HIGH AS 50 MPH.
* WHERE...GREEN MOUNTAINS AND RATTLESNAKE RANGE.
* WHEN...UNTIL 6 PM MDT THIS EVENING.
* IMPACTS...TRAVEL WILL BE DIFFICULT DUE TO A COMBINATION OF WIND
AND FALLING SNOW.
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
1246 PM 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 1 AND
3 INCHES. AREAS OF HIGHER AMOUNTS UP TO 4 INCHES BETWEEN HILAND
AND CASPER AND FOR 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. 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-
1246 PM 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
3 AND 6 INCHES POSSIBLE. WINDS COULD GUST AS HIGH AS 40 MPH.
* WHERE...CASPER MOUNTAIN.
* WHEN...UNTIL 6 PM MDT THIS EVENING.
* IMPACTS...TRAVEL WILL BE VERY DIFFICULT. AREAS OF BLOWING SNOW
COULD SIGNIFICANTLY REDUCE VISIBILITY. 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
1246 PM 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
1 AND 3 INCHES. LOWER AMOUNTS UP TO 1 INCH 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.
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 .
WYZ014-190000-
/O.CON.KRIW.WW.Y.0019.000000T0000Z-260519T0000Z/
WIND RIVER MOUNTAINS WEST-
1246 PM MDT MON MAY 18 2026
...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM MDT THIS
EVENING...
* WHAT...SNOW EXPECTED. ADDITIONAL SNOW ACCUMULATIONS BETWEEN 3 AND
5 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 EVENING 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 .
WYZ026-190000-
/O.CON.KRIW.WW.Y.0019.000000T0000Z-260519T0000Z/
UPPER GREEN RIVER BASIN-
INCLUDING THE CITIES OF BIG PINEY, LA BARGE, AND FARSON
1246 PM 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 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.
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 COKEVILLE AND KEMMERER
1246 PM 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 1 INCH.
WINDS GUSTING AS HIGH AS 40 MPH.
* WHERE...SOUTH LINCOLN COUNTY.
* WHEN...UNTIL 6 PM MDT THIS EVENING.
* IMPACTS...TRAVEL COULD BE DIFFICULT DUE TO A COMBINATION OF WIND
AND FALLING SNOW.
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 GREEN RIVER AND ROCK SPRINGS
1246 PM 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 1 INCH.
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 EVENING
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/ .
WITTMANN
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