Freezing Fog Advisory

URGENT - WEATHER MESSAGE
National Weather Service Pendleton OR
353 PM PST Tue Jan 20 2026

ORZ050-211500-
/O.EXB.KPDT.ZF.Y.0010.000000T0000Z-260121T1700Z/
Wallowa County-
Including the cities of Enterprise, Joseph, and Wallowa
353 PM PST Tue Jan 20 2026

...FREEZING FOG ADVISORY IN EFFECT UNTIL 9 AM PST WEDNESDAY WALLOWA
VALLEY...

* WHAT...Visibility a mile or less in freezing fog in the Wallowa
  Valley.

* WHERE...Wallowa County.

* WHEN...Until 9 AM PST Wednesday.

* 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.

&&

$$

BL

Air Stagnation Advisory

URGENT - WEATHER MESSAGE
National Weather Service Boise ID
147 PM MST Tue Jan 20 2026

IDZ011>014-016-028-033-ORZ061>064-211400-
/O.EXT.KBOI.AS.Y.0001.000000T0000Z-260123T1200Z/
West Central Mountains-Lower Treasure Valley-Boise Mountains-
Upper Treasure Valley-Western Magic Valley-Camas Prairie-Upper
Weiser River-Harney County-Baker County-Malheur County-Oregon
Lower Treasure Valley-
Including the cities of Warm Lake, Cambridge, Bear, Goodrich,
Hill City, Venator, Corral, Nampa, Indian Valley, Nyssa, Soldier,
Twin Falls, Cuprum, Baker, Burns, Boise, Glendale, Mesa,
Caldwell, Ola, Blaine, Dunnean, New Princeton, Fairfield,
Anderson Dam, Pine, Big Creek, Cascade, McCall, Malheur City,
Ontario, Prairie, Council, Selby, Crane, Diamond, Fruitvale, and
Buchanan
147 PM MST Tue Jan 20 2026 /1247 PM PST Tue Jan 20 2026/

...AIR STAGNATION ADVISORY NOW IN EFFECT UNTIL 5 AM MST /4 AM PST/
FRIDAY...

* WHAT...An extended period of stagnant air, with light winds and
  little vertical mixing. This is due to an inversion near the
  surface that will continue to trap pollutants.

* WHERE...Portions of south central and southwest Idaho and
  northeast and southeast Oregon.

* WHEN...Until 5 AM MST /4 AM PST/ Friday.

* IMPACTS...Poor air quality may cause issues for people with
  respiratory problems.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Persons with respiratory illness should follow their physicians
advice for dealing with high levels of air pollution during periods
of stagnant air.

&&

$$

LC

URGENT - WEATHER MESSAGE
National Weather Service Pocatello ID
931 AM MST Tue Jan 20 2026

IDZ054-059-221900-
/O.EXT.KPIH.AS.Y.0001.000000T0000Z-260122T1900Z/
Lower Snake River Plain-Franklin/Eastern Oneida Region-
Including the cities of Pocatello, Blackfoot, Shelley, Fort Hall,
Malad, Preston, American Falls, and Thatcher
931 AM MST Tue Jan 20 2026

...AIR STAGNATION ADVISORY NOW IN EFFECT UNTIL NOON MST THURSDAY...

* WHAT...Stagnant conditions will persist due to little vertical
  mixing and light winds. Degraded air quality is expected to
  continue as pollutants remained trapped near the surface.

* WHERE...Franklin/Eastern Oneida Region and Lower Snake River Plain.

* WHEN...Until noon MST Thursday.

* IMPACTS...Periods of air stagnation can lead to the buildup of
  pollutants near the surface.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If possible, reduce or eliminate activities that contribute to air
pollution, such as outdoor burning, and the use of residential wood
burning devices. Reduce vehicle trips and vehicle idling as much as
possible. Check with local agencies for possible restrictions in
your area.

&&

$$

Visit weather.gov/pocatello for more information.

McKaughan

Hazardous Weather Outlook

Hazardous Weather Outlook
National Weather Service Riverton WY
258 AM MST Tue Jan 20 2026

WYZ001>020-022>030-211400-
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-
258 AM MST Tue Jan 20 2026

This Hazardous Weather Outlook is for Western and Central Wyoming.

.DAY ONE...Rest of Tonight.

Gusty to strong wind across much of the area this afternoon. Snow
may cause difficult travel conditions in Johnson County from late
this morning into early afternoon.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Thursday and Friday...Colder temperatures returning East of the
Divide.

.SPOTTER INFORMATION STATEMENT...

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

$$