Dense Fog Advisory

URGENT - WEATHER MESSAGE
National Weather Service Glasgow MT
419 AM MST Thu Nov 20 2025

MTZ017-020-201700-
/O.NEW.KGGW.FG.Y.0008.251120T1119Z-251120T1700Z/
Central and Southern Valley-Western Roosevelt-
Including Poplar, Wolf Point, Frazer, Fort Peck, Glasgow, and
Hinsdale
419 AM MST Thu Nov 20 2025

...DENSE FOG ADVISORY IN EFFECT UNTIL 10 AM MST THIS MORNING...

* WHAT...Visibility 1/4 to 2 miles in dense fog.

* WHERE...Central and Southern Valley and Western Roosevelt Counties.

* WHEN...Until 10 AM MST this morning.

* IMPACTS...Low visibility could make driving conditions hazardous.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If driving, slow down, use your headlights, and leave plenty of
distance ahead of you.

&&

$$

GAH

Special Weather Statement

Special Weather Statement
National Weather Service Great Falls MT
726 AM MST Thu Nov 20 2025

MTZ315-320-322-325-201630-
Upper Blackfoot and MacDonald Pass-
Big Belt, Bridger and Castle Mountains-
Elkhorn and Boulder Mountains-Madison River Valley-
Including the cities of Marysville, Lincoln, Flesher Pass,
MacDonald Pass, Trident, Maudlow, Battle Ridge Pass,
Bozeman Pass, Deep Creek Pass, Montana City, Clancy, Boulder,
Corbin, Wickes, Elk Park Pass, Homestake Pass, Cameron, Ennis,
Jeffers, McAllister, and Norris
726 AM MST Thu Nov 20 2025

...Patchy dense fog will continue over the Madison River Valley
and mountain passes across central and southwest Montana through
mid-morning...

Patchy dense fog will continue over the Madison River Valley and
mountain passes across central and southwest Montana through mid-
morning. Variable visibility down to a quarter mile can be
expected.

Those with travel plans this morning should be prepared for
highly variable road conditions, including visibility reductions
down to a quarter mile. Slow down and allow extra time to reach
your destination.

$$

Special Weather Statement
National Weather Service Riverton WY
307 AM MST Thu Nov 20 2025

WYZ013-017>020-023-025>028-201700-
Jackson Hole-Wind River Basin-Lander Foothills-
Green Mountains and Rattlesnake Range-
Natrona County Lower Elevations-Star Valley-
Upper Green River Basin Foothills-Upper Green River Basin-
South Lincoln County-Rock Springs and Green River-
Including the cities of Jackson, Riverton, Shoshoni, Lander,
Jeffrey City, Casper, Afton, Alpine, Star Valley Ranch, Thayne,
Pinedale, La Barge, Big Piney, Farson, Kemmerer, Cokeville,
Rock Springs, and Green River
307 AM MST Thu Nov 20 2025

...PATCHY AREAS OF FOG THIS MORNING ACROSS PORTIONS OF WESTERN,
SOUTHERN, AND CENTRAL WYOMING...

Clearing skies and ample moisture have led to the development of
patchy areas of fog across portions of the state this morning.
Visibilities of less than one mile have already been observed
along US 20/26 from Casper to Hiland. Other locations such as Star
Valley have seen fog develop, leading to reduced visibilities of
less than one mile as well.

* WHAT...Patchy areas of fog leading to decreased visibilities of
  less than one mile.

* WHERE...Portions of Western, Southern, and Central WY. Locations
  such as Star Valley, Jackson Hole, Green River Basin, Wind River
  Basin, and Natrona County.

* WHEN...Through 10 AM Thursday.

* ADDITIONAL DETAILS... If needing to drive through these areas
  this morning, allow extra time for your commute and be prepared
  for sudden drops in visibility. Slow down, use low beam
  headlights, and leave extra space between you and other
  motorists.

$$

Hazardous Weather Outlook

Hazardous Weather Outlook
National Weather Service Riverton WY
314 AM MST Thu Nov 20 2025

WYZ001>020-022>030-211415-
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-
314 AM MST Thu Nov 20 2025

...Special Weather Statement Due to Patchy Areas of Fog Has Been
Posted for Portions of Western, Southern, and Central WY to 10 AM
Thursday...

This Hazardous Weather Outlook is for Western and Central Wyoming.

.DAY ONE...Today and tonight.

Patchy areas of fog with visibilities less than one mile have begun
to develop across portions of western, southern, and central WY this
morning. Fog will likely linger through the morning gradually
dissipating by the late morning hours. Isolated showers will be
possible this morning mainly over western and southern WY.

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

Friday... Near seasonable temperatures with scattered showers
possible across portions of western and southern WY.

.SPOTTER INFORMATION STATEMENT...

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

$$