Red Flag Warning
URGENT - FIRE WEATHER MESSAGE
National Weather Service Pocatello ID
1241 PM MDT Fri Aug 21 2026
...CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED ON SATURDAY DUE
TO SCATTERED THUNDERSTORM ACTIVITY ACROSS MUCH OF EASTERN
IDAHO...
IDZ410-422-425-427-475-476-221200-
/O.NEW.KPIH.FW.W.0022.260822T1800Z-260823T0300Z/
Upper Snake River Valley/Idaho Falls BLM-
Sawtooth Range/Northern Sawtooth NF-
Middle Snake River Valley/Twin Falls BLM north of the Snake River-
Goose Creek and Raft River Valley/Southern Sawtooth NF/Twin Falls
BLM south of the Snake River-
East Salmon River Mountains/Salmon NF-
Lemhi and Lost River Range/Challis NF-
1241 PM MDT Fri Aug 21 2026
...RED FLAG WARNING IN EFFECT FROM NOON TO 9 PM MDT SATURDAY FOR
SCATTERED THUNDERSTORMS FOR FIRE WEATHER ZONES 410, 422, 425,
427, 475, AND 476...
The National Weather Service in Pocatello has issued a Red Flag
Warning for scattered thunderstorms, which is in effect from noon
to 9 PM MDT Saturday.
* AFFECTED AREA...Fire Weather Zone 410 Upper Snake River
Valley/Idaho Falls BLM, Fire Weather Zone 422 Sawtooth
Range/Northern Sawtooth NF, Fire Weather Zone 425 Middle Snake
River Valley/Twin Falls BLM north of the Snake River, Fire
Weather Zone 427 Goose Creek and Raft River Valley/Southern
Sawtooth NF/Twin Falls BLM south of the Snake River, Fire
Weather Zone 475 East Salmon River Mountains/Salmon NF and
Fire Weather Zone 476 Lemhi and Lost River Range/Challis NF.
* IMPACTS...Frequent lightning will increase risk of new fire
starts.
* THUNDERSTORMS...Scattered coverage with frequent lightning.
* OUTFLOW WINDS...Gusty and erratic winds to 60 mph.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:
- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.
- Thunderstorm coverage of 25 percent, without specific rainfall
criteria.
- Other high impact events deemed critical by the National
Weather Service and area fire management agencies.
&&
$$
Heat Advisory
URGENT - WEATHER MESSAGE
National Weather Service Salt Lake City UT
1234 PM MDT Fri Aug 21 2026
UTZ101>106-221300-
/O.CON.KSLC.HT.Y.0008.000000T0000Z-260822T1300Z/
Great Salt Lake Desert and Mountains-Tooele and Rush Valleys-
Eastern Box Elder County-Northern Wasatch Front-Salt Lake Valley-
Utah Valley-
Including the following locations - Dugway, Park Valley, Salt
Lake City, Payson, Snowville, Tooele, Ogden, Bountiful, West Jordan,
Provo, Brigham City, Vernon, Wendover, Lehi, Grantsville, and Sandy
1234 PM MDT Fri Aug 21 2026
...HEAT ADVISORY REMAINS IN EFFECT UNTIL 7 AM MDT SATURDAY...
* WHAT...High temperatures to around 100 degrees expected alongside
overnight low temperatures in the low- to mid-70s.
* WHERE...The Wasatch Front, Great Salt Lake Desert and Mountains,
and Tooele and Rush Valleys.
* WHEN...Until 7 AM MDT Saturday.
* IMPACTS...Hot temperatures may cause heat illness. Warm overnight
temperatures will limit the amount of relief from the hot daytime
temperatures, bringing a period of prolonged heat exposure,
especially for vulnerable populations.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.
Take extra precautions when outside. Wear lightweight and loose
fitting clothing. Try to limit strenuous activities to early morning
or evening. Take action when you see symptoms of heat exhaustion and
heat stroke.
To reduce risk during outdoor work, the Occupational Safety and
Health Administration recommends scheduling frequent rest breaks in
shaded or air conditioned environments. Anyone overcome by heat
should be moved to a cool and shaded location. Heat stroke is an
emergency! Call 9 1 1.
&&
$$
For more information from the National Weather Service visit
https://weather.gov/saltlakecity.
For information on potential travel impacts visit
http://udottraffic.utah.gov
Webber
URGENT - WEATHER MESSAGE
National Weather Service Pocatello ID
201 AM MDT Fri Aug 21 2026
IDZ051-054>057-075-220400-
/O.CON.KPIH.HT.Y.0007.260821T1800Z-260822T0400Z/
Shoshone/Lava Beds-Lower Snake River Plain-Eastern Magic Valley-
Southern Hills/Albion Mountains-Raft River Region-Wood River
Foothills-
Including the cities of Fort Hall, Hailey, Burley, Albion, Shelley,
Pocatello, Oakley, Bellevue, Carey, Picabo, Almo, Malta, American
Falls, Richfield, Rockland, Heyburn, Rupert, Blackfoot, Holbrook, and
Shoshone
201 AM MDT Fri Aug 21 2026
...HEAT ADVISORY REMAINS IN EFFECT FROM NOON TODAY TO 10 PM MDT THIS
EVENING...
* WHAT...Temperatures up to 98 expected.
* WHERE...Wood River Foothills, Eastern Magic Valley, Shoshone/Lava
Beds, Lower Snake River Plain, Raft River Region, and Southern
Hills/Albion Mountains.
* WHEN...From noon today to 10 PM MDT this evening.
* IMPACTS...Hot temperatures may cause heat illnesses, including
heatstroke and heat exhaustion.
$$
URGENT - WEATHER MESSAGE
National Weather Service Pocatello ID
201 AM MDT Fri Aug 21 2026
IDZ052-053-058-059-220400-
/O.CON.KPIH.HT.Y.0007.260821T1800Z-260822T0400Z/
Arco/Mud Lake Desert-Upper Snake River Plain-Marsh and Arbon
Highlands-Franklin/Eastern Oneida Region-
Including the cities of Thatcher, Preston, Rexburg, Lava Hot
Springs, Idaho Falls, Downey, INL, St. Anthony, Mud Lake, Craters
of the Moon NM, Inkom, Malad, and McCammon
201 AM MDT Fri Aug 21 2026
...HEAT ADVISORY REMAINS IN EFFECT FROM NOON TODAY TO 10 PM MDT THIS
EVENING...
* WHAT...Temperatures up to 95 expected.
* WHERE...Arco/Mud Lake Desert, Franklin/Eastern Oneida Region, Marsh
and Arbon Highlands, and Upper Snake River Plain.
* WHEN...From noon today to 10 PM MDT this evening.
* IMPACTS...Hot temperatures may cause heat illnesses, including
heatstroke and heat exhaustion.
$$
Visit weather.gov/pocatello for more information.
Messick
URGENT - WEATHER MESSAGE
National Weather Service Pocatello ID
201 AM MDT Fri Aug 21 2026
IDZ061-062-064-065-067-220400-
/O.EXA.KPIH.HT.Y.0007.260821T1800Z-260822T0400Z/
Bear Lake Valley-Blackfoot Mountains-Big Hole Mountains-Teton
Valley-Beaverhead - Lemhi Highlands-
Including the cities of Montpelier, Edie School, Soda Springs,
Georgetown, Driggs, Dubois, Bone, Spencer, St. Charles, Ashton,
Small, Grace, Victor, Tetonia, and Henry
201 AM MDT Fri Aug 21 2026
...HEAT ADVISORY IN EFFECT FROM NOON TODAY TO 10 PM MDT THIS
EVENING...
* WHAT...Temperatures up to 95 expected.
* WHERE...Beaverhead - Lemhi Highlands, Big Hole Mountains, Teton
Valley, Bear Lake Valley, and Blackfoot Mountains.
* WHEN...From noon today to 10 PM MDT this evening.
* IMPACTS...Hot temperatures may cause heat illnesses.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.
&&
$$
URGENT - WEATHER MESSAGE
National Weather Service Boise ID
216 PM MDT Thu Aug 20 2026
IDZ012-014-016-033-ORZ064-212115-
/O.CON.KBOI.HT.Y.0007.000000T0000Z-260822T0300Z/
Lower Treasure Valley-Upper Treasure Valley-Western Magic Valley-
Upper Weiser River-Oregon Lower Treasure Valley-
Including the cities of Nampa, Boise, Indian Valley, Council,
Glendale, Cambridge, Ontario, Caldwell, Nyssa, Goodrich, Twin Falls,
Fruitvale, and Mesa
216 PM MDT Thu Aug 20 2026 /116 PM PDT Thu Aug 20 2026/
...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM MDT /8 PM PDT/
FRIDAY...
* WHAT...High temperatures 98 to 104 degrees both today and Friday.
* WHERE...Portions of south central and southwest Idaho and southeast
Oregon.
* WHEN...Until 9 PM MDT /8 PM PDT/ Friday.
* IMPACTS...Hot temperatures may cause heat illnesses.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Drink plenty of fluids, stay in an air-conditioned room, stay out of
the sun, and check up on relatives and neighbors.
Take extra precautions when outside. Wear lightweight and loose
fitting clothing. Try to limit strenuous activities to early morning
or evening. Take action when you see symptoms of heat exhaustion and
heat stroke.
To reduce risk during outdoor work, the Occupational Safety and
Health Administration recommends scheduling frequent rest breaks in
shaded or air conditioned environments. Anyone overcome by heat
should be moved to a cool and shaded location. Heat stroke is an
emergency! Call 9 1 1.
&&
$$
LC
