257 
WGUS65 KPIH 181630
FFAPIH

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Pocatello ID
1030 AM MDT Fri Sep 18 2026

IDZ053-190600-
/O.CAN.KPIH.FF.A.0007.000000T0000Z-260919T0400Z/
/O.NEW.KPIH.FA.A.0002.260918T1630Z-260919T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Upper Snake River Plain-
Including the cities of Rexburg, Idaho Falls, and St. Anthony
1030 AM MDT Fri Sep 18 2026

...FLASH FLOOD WATCH FOR THE BIG ROCK BURN SCAR IS BEING EXPANDED...

The Flash Flood Watch for the Big Rock burn scar is being replaced
with a more broad Flash Flood Watch across eastern Idaho.

&&

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

* WHAT...Flash flooding caused by excessive rainfall is possible.

* WHERE...A portion of southeast Idaho, including the following area,
  Upper Snake River Plain.

* WHEN...Through this evening.

* IMPACTS...Excessive runoff may result in flooding of rivers,
  creeks, streams, and other low-lying and flood-prone locations.
  Flooding may occur in poor drainage and urban areas. Storm drains
  and ditches may become clogged with debris.

* ADDITIONAL DETAILS...
  - Heavy rainfall from thunderstorms is expected through this
    evening across eastern Idaho. Rainfall amounts in excess of 0.50"
    are possible, leading to flooding within burn scars, steep
    terrain, and urban areas.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$

IDZ052-054-058>068-070>073-075-190600-
/O.NEW.KPIH.FA.A.0002.260918T1630Z-260919T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Arco/Mud Lake Desert-Lower Snake River Plain-Marsh and Arbon
Highlands-Franklin/Eastern Oneida Region-Bear River Range-Bear
Lake Valley-Blackfoot Mountains-Caribou Range-Big Hole Mountains-
Teton Valley-Centennial Mountains - Island Park-Beaverhead -
Lemhi Highlands-Lost River Valley-Challis/Pahsimeroi Valleys-
Frank Church Wilderness-Sawtooth/Stanley Basin-Sun Valley Region-
Wood River Foothills-
Including the cities of Montpelier, Craters of the Moon NM, Shelley,
Downey, Tetonia, Chilly, Arco, Malad, Victor, Emigration Summit,
Grace, Stanley, INL, Challis, Kilgore, Blackfoot, Spencer, Dubois,
Georgetown, Lava Hot Springs, American Falls, Preston, Small, Fort
Hall, Galena, Driggs, Soda Springs, McCammon, Island Park, Clayton,
Bellevue, Picabo, Sun Valley, Mud
Lake, Pocatello, St. Charles, Bone, Henry, Howe, Ashton, Wayan,
Mackay, Thatcher, Hailey, Swan Valley, Inkom, Ketchum, and Edie
School
1030 AM MDT Fri Sep 18 2026

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

* WHAT...Flash flooding caused by excessive rainfall is possible.

* WHERE...Portions of central, eastern, and southeast Idaho,
  including the following areas, in central Idaho, Challis/Pahsimeroi
  Valleys, Frank Church Wilderness, Lost River Valley,
  Sawtooth/Stanley Basin, Sun Valley Region and Wood River Foothills.
  In eastern Idaho, Beaverhead - Lemhi Highlands, Big Hole Mountains,
  Centennial Mountains - Island Park and Teton Valley. In southeast
  Idaho, Arco/Mud Lake Desert, Bear Lake Valley, Bear River Range,
  Blackfoot Mountains, Caribou Range, Franklin/Eastern Oneida Region,
  Lower Snake River Plain and Marsh and Arbon Highlands.

* WHEN...Through this evening.

* IMPACTS...Excessive runoff may result in flooding of rivers,
  creeks, streams, and other low-lying and flood-prone locations.
  Flooding may occur in poor drainage and urban areas. Storm drains
  and ditches may become clogged with debris.

* ADDITIONAL DETAILS...
  - Heavy rainfall from thunderstorms is expected through this
    evening across central and eastern Idaho. Rainfall amounts in
    excess of 0.50" are possible, leading to flooding within burn
    scars, steep terrain, and urban areas.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$

JKeyes

257 
WGUS65 KPIH 181630
FFAPIH

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Pocatello ID
1030 AM MDT Fri Sep 18 2026

IDZ053-190600-
/O.CAN.KPIH.FF.A.0007.000000T0000Z-260919T0400Z/
/O.NEW.KPIH.FA.A.0002.260918T1630Z-260919T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Upper Snake River Plain-
Including the cities of Rexburg, Idaho Falls, and St. Anthony
1030 AM MDT Fri Sep 18 2026

...FLASH FLOOD WATCH FOR THE BIG ROCK BURN SCAR IS BEING EXPANDED...

The Flash Flood Watch for the Big Rock burn scar is being replaced
with a more broad Flash Flood Watch across eastern Idaho.

&&

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

* WHAT...Flash flooding caused by excessive rainfall is possible.

* WHERE...A portion of southeast Idaho, including the following area,
  Upper Snake River Plain.

* WHEN...Through this evening.

* IMPACTS...Excessive runoff may result in flooding of rivers,
  creeks, streams, and other low-lying and flood-prone locations.
  Flooding may occur in poor drainage and urban areas. Storm drains
  and ditches may become clogged with debris.

* ADDITIONAL DETAILS...
  - Heavy rainfall from thunderstorms is expected through this
    evening across eastern Idaho. Rainfall amounts in excess of 0.50"
    are possible, leading to flooding within burn scars, steep
    terrain, and urban areas.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$

IDZ052-054-058>068-070>073-075-190600-
/O.NEW.KPIH.FA.A.0002.260918T1630Z-260919T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Arco/Mud Lake Desert-Lower Snake River Plain-Marsh and Arbon
Highlands-Franklin/Eastern Oneida Region-Bear River Range-Bear
Lake Valley-Blackfoot Mountains-Caribou Range-Big Hole Mountains-
Teton Valley-Centennial Mountains - Island Park-Beaverhead -
Lemhi Highlands-Lost River Valley-Challis/Pahsimeroi Valleys-
Frank Church Wilderness-Sawtooth/Stanley Basin-Sun Valley Region-
Wood River Foothills-
Including the cities of Montpelier, Craters of the Moon NM, Shelley,
Downey, Tetonia, Chilly, Arco, Malad, Victor, Emigration Summit,
Grace, Stanley, INL, Challis, Kilgore, Blackfoot, Spencer, Dubois,
Georgetown, Lava Hot Springs, American Falls, Preston, Small, Fort
Hall, Galena, Driggs, Soda Springs, McCammon, Island Park, Clayton,
Bellevue, Picabo, Sun Valley, Mud
Lake, Pocatello, St. Charles, Bone, Henry, Howe, Ashton, Wayan,
Mackay, Thatcher, Hailey, Swan Valley, Inkom, Ketchum, and Edie
School
1030 AM MDT Fri Sep 18 2026

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

* WHAT...Flash flooding caused by excessive rainfall is possible.

* WHERE...Portions of central, eastern, and southeast Idaho,
  including the following areas, in central Idaho, Challis/Pahsimeroi
  Valleys, Frank Church Wilderness, Lost River Valley,
  Sawtooth/Stanley Basin, Sun Valley Region and Wood River Foothills.
  In eastern Idaho, Beaverhead - Lemhi Highlands, Big Hole Mountains,
  Centennial Mountains - Island Park and Teton Valley. In southeast
  Idaho, Arco/Mud Lake Desert, Bear Lake Valley, Bear River Range,
  Blackfoot Mountains, Caribou Range, Franklin/Eastern Oneida Region,
  Lower Snake River Plain and Marsh and Arbon Highlands.

* WHEN...Through this evening.

* IMPACTS...Excessive runoff may result in flooding of rivers,
  creeks, streams, and other low-lying and flood-prone locations.
  Flooding may occur in poor drainage and urban areas. Storm drains
  and ditches may become clogged with debris.

* ADDITIONAL DETAILS...
  - Heavy rainfall from thunderstorms is expected through this
    evening across central and eastern Idaho. Rainfall amounts in
    excess of 0.50" are possible, leading to flooding within burn
    scars, steep terrain, and urban areas.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$

JKeyes

574 
WGUS65 KPIH 190032
FFAPIH

Flood Watch
National Weather Service Pocatello ID
632 PM MDT Fri Sep 18 2026

IDZ052>054-058>068-070>073-075-190145-
/O.CAN.KPIH.FA.A.0002.000000T0000Z-260919T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Arco/Mud Lake Desert-Upper Snake River Plain-Lower Snake River
Plain-Marsh and Arbon Highlands-Franklin/Eastern Oneida Region-
Bear River Range-Bear Lake Valley-Blackfoot Mountains-Caribou
Range-Big Hole Mountains-Teton Valley-Centennial Mountains -
Island Park-Beaverhead - Lemhi Highlands-Lost River Valley-
Challis/Pahsimeroi Valleys-Frank Church Wilderness-
Sawtooth/Stanley Basin-Sun Valley Region-Wood River Foothills-
Including the cities of Ashton, Malad, Edie School, Fort Hall, Grace,
Sun Valley, Arco, Island Park, Soda Springs, Picabo, Bone,
St. Anthony, American Falls, Emigration Summit, INL, Tetonia,
Craters of the Moon NM, Small, Henry, Lava Hot Springs, Howe, Mackay,
Galena, Preston, Georgetown, Mud Lake, Clayton, Stanley, Spencer,
Victor, Ketchum, Bellevue, Montpelier, Chilly, Challis, Kilgore,
Downey, Dubois, Idaho Falls, Blackfoot, Inkom, Rexburg,
Swan Valley, Driggs, Hailey, St. Charles, Wayan, Shelley,
Pocatello, McCammon, and Thatcher
632 PM MDT Fri Sep 18 2026

...FLOOD WATCH IS CANCELLED...

THE AREA WAS TOO STABLE TODAY WITH TOO MUCH CLOUD COVER EARLY IN THE
DAY. THUS, THUNDERSTORMS DIDNT DEVELOP THE WAY MODELS SHOWED THAT
THEY WOULD. THERE WILL BE LIGHT SHOWERS OVERNIGHT ESPECIALLY ALONG
THE WYOMING BORDER, MONTANA DIVIDE AND THE NORTHERN CENTRAL
MOUNTAINS. AS THE UPPER LEVEL LOW THAT IS DIRECTLY OVERHEAD CURRENTLY
SHIFTS EAST OVERNIGHT INTO TOMORROW, LIGHT TO MODERATE SHOWERS ARE
POSSIBLE IN THE MORNING, ESPECIALLY THE EASTERN BENCHES OF THE SNAKE
PLAIN AND THE EASTERN HIGHLANDS ALONG THE WYOMING BORDER. MODELS SHOW
ISOLATE THUNDERSTORM DEVELOPMENT TOMORROW AFTERNOON MAINLY IN THE
MOUNTAINS ALONG THE EASTERN HIGHLANDS NEXT TO THE WYOMING BORDER.

The Flood Watch is cancelled for portions of central, eastern, and
southeast Idaho, including the following areas, in central Idaho,
Challis/Pahsimeroi Valleys, Frank Church Wilderness, Lost River
Valley, Sawtooth/Stanley Basin, Sun Valley Region and Wood River
Foothills. In eastern Idaho, Beaverhead - Lemhi Highlands, Big Hole
Mountains, Centennial Mountains - Island Park and Teton Valley. In
southeast Idaho, Arco/Mud Lake Desert, Bear Lake Valley, Bear River
Range, Blackfoot Mountains, Caribou Range, Franklin/Eastern Oneida
Region, Lower Snake River Plain, Marsh and Arbon Highlands and Upper
Snake River Plain.

Flooding is no longer expected to pose a threat. Please continue to
heed remaining road closures.

$$

TW