Hazard Report Provided By forecast.weather.gov

Hazardous Weather Outlook
National Weather Service Riverton WY
457 AM MST Thu Dec 18 2025

WYZ001>020-022>030-191600-
Yellowstone National Park-Absaroka Mountains-Cody Foothills-
North Bighorn Basin-Southwest Bighorn Basin-Southeast Bighorn Basin-
Owl Creek and Bridger Mountains-Bighorn Mountains West-
Bighorn Mountains Southeast-Northeast Johnson County-
Southeast Johnson County-Teton and Gros Ventre Mountains-
Jackson Hole-Wind River Mountains West-Wind River Mountains East-
Upper Wind River Basin-Wind River Basin-Lander Foothills-
Green Mountains and Rattlesnake Range-
Natrona County Lower Elevations-Casper Mountain-Star Valley-
Salt River and Wyoming Ranges-Upper Green River Basin Foothills-
Upper Green River Basin-South Lincoln County-
Rock Springs and Green River-Flaming Gorge-East Sweetwater County-
457 AM MST Thu Dec 18 2025

...WINTER STORM WARNING IN EFFECT FOR THE MOUNTAINS OF WESTERN WY
FROM 11 AM THIS MORNING TO 5 AM MST SATURDAY...

...WINTER WEATHER ADVISORY IN EFFECT FOR WESTERN VALLEYS OF WESTERN
WY FROM 11 AM THIS MORNING TO 5 AM MST SATURDAY...

This Hazardous Weather Outlook is for Western and Central Wyoming.

.DAY ONE...Today and tonight.

Another weather system enters the region with snow arriving across
western WY by the afternoon. Periods of moderate to heavy snowfall
will be possible by the evening through the overnight. Gusty winds
begin to develop this afternoon over the Wind Corridor from Casper
to Rock Springs with gusts of 35 to 45 mph.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Friday through Saturday Morning...Heavy snowfall continues across the
higher elevation mountains of western WY. Precipitation will be
periodic for western valleys with temperatures expected to warm
through the day Friday. A transition to a mix or rain/snow or wet
snow is possible which may hinder any further accumulation. Winds
increase during the morning with widespread gusty winds expected
through the day. High winds may be possible across portions of
central and northern WY. Eastern slopes of the Wind River, Absaroka,
and Bighorn Ranges including locations such as Lander, Cody, and
Buffalo may see a gusts of 60 mph or more. A cold front passage
during the late evening and early morning on Saturday may produce
some chances for showers east of the Divide. Temperatures may be cold
enough for snow with minimal impacts expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

$$

URGENT - WINTER WEATHER MESSAGE
National Weather Service Riverton WY
124 AM MST Thu Dec 18 2025

WYZ013-023-190030-
/O.NEW.KRIW.WW.Y.0038.251218T1800Z-251220T1200Z/
Jackson Hole-Star Valley-
Including the cities of Star Valley Ranch, Alpine, Jackson,
Afton, and Thayne
124 AM MST Thu Dec 18 2025

...WINTER WEATHER ADVISORY IN EFFECT FROM 11 AM THIS MORNING TO 5 AM
MST SATURDAY...

* WHAT...Snow expected. Total snow accumulations of 4 to 8 inches
  with locally higher amounts of 10 to 14 inches in the higher
  elevations and along the foothills. Winds gusting as high as 45
  mph at times.

* WHERE...Jackson Hole and Star Valley.

* WHEN...From 11 AM this morning to 5 AM MST Saturday.

* IMPACTS...Travel could be difficult. The hazardous conditions
  could impact the Thursday evening and Friday morning as well as
  evening commutes.

* ADDITIONAL DETAILS...Temperatures may warm above freezing during
  the daytime Friday which would lead to a possible transition over
  to a mix of rain/snow or heavy wet snow. Accumulations may be
  limited during this time but slick conditions could still be
  possible.

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 .

&&

$$

Hazard Report Provided By forecast.weather.gov