Alert archive / Idaho / Winter Storm Warnings in 2021

Winter Storm Warning 7, NWS Pocatello, ID

October 23, 2021Blaine County, Butte County, Custer County, Idaho

NWS Pocatello, ID issued this winter storm warning at Oct 23, 2021, 2:21 PM MDT for Blaine County, Butte County, Custer County, Idaho. It took effect at Oct 24, 2021, 12:00 PM MDT. It was in force for 24 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Oct 23, 2021, 2:21 PM MDT (20:21 UTC)
In effect from
Oct 24, 2021, 12:00 PM MDT
Expired
Oct 25, 2021, 12:00 PM MDT
In force
24 hr
Issued by
NWS Pocatello, ID

Counties Blaine County, ID, Butte County, ID, Custer County, ID

The radar

The Pocatello radar (KSFX), 119 km from the middle of the area, began a volume at 20:23 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Boise Airport, ID (KBOI), launched 12:00Z, 8.4 hours before the alert went out and 194 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Boise Airport, ID at 12:00Z on 2021-10-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Boise Airport, ID at 12:00Z on 2021-10-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1020 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
46 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

255 
WWUS45 KPIH 232021
WSWPIH

URGENT - WINTER WEATHER MESSAGE
National Weather Service Pocatello ID
221 PM MDT Sat Oct 23 2021

IDZ069-071>074-241300-
/O.UPG.KPIH.WS.A.0005.211024T1800Z-211025T1800Z/
/O.NEW.KPIH.WS.W.0007.211024T1800Z-211025T1800Z/
Lost River Range-Frank Church Wilderness-Sawtooth/Stanley Basin-
Sun Valley Region-Big Lost Highlands/Copper Basin-
Including the cities of Borah Peak, Clayton, Stanley, Ketchum, 
Sun Valley, Galena, and Copper Basin
221 PM MDT Sat Oct 23 2021

...WINTER STORM WARNING IN EFFECT FROM NOON SUNDAY TO NOON MDT
MONDAY...

* WHAT...Heavy wet snow expected. Total snow accumulations of up
  to 3 inches below 7000 feet with 3-12 inches above 7000 feet 
  and locally higher amounts near peaks and ridges. Winds could 
  gust as high as 35 MPH with localized blowing snow, especially 
  as you increase in elevation.

* WHERE...Portions of the Idaho central mountains, including but 
  not limited to the Frank Church Wilderness, Banner Summit, 
  Sawtooth Mountains, Galena Summit, the Big Lost Highlands, and 
  Lost River Range.

* WHEN...From noon Sunday to noon MDT Monday.

* IMPACTS...While slick conditions and light accumulations may
  occur down into Stanley, Ketchum, and Sun Valley during this
  event, the greatest concern for very difficult travel will exist
  over Galena Summit, as well as for local and backcountry roads
  above about 7,000 feet. In addition, the heavy, wet nature of 
  the snow may strain weaker structures and tree limbs.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions can be obtained by calling 5 1 1.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/pocatello
3 follow-up statements
622 
WWUS45 KPIH 240832
WSWPIH

URGENT - WINTER WEATHER MESSAGE
National Weather Service Pocatello ID
232 AM MDT Sun Oct 24 2021

IDZ069-071>074-242300-
/O.CON.KPIH.WS.W.0007.211024T1800Z-211025T1800Z/
Lost River Range-Frank Church Wilderness-Sawtooth/Stanley Basin-
Sun Valley Region-Big Lost Highlands/Copper Basin-
Including the cities of Borah Peak, Clayton, Stanley, Ketchum, 
Sun Valley, Galena, and Copper Basin
232 AM MDT Sun Oct 24 2021

...WINTER STORM WARNING REMAINS IN EFFECT FROM NOON TODAY TO NOON
MDT MONDAY...

* WHAT...Heavy wet snow expected. Total snow accumulations of up 
  to 3 inches below 7000 feet with 3-12 inches above 7000 feet 
  and locally higher amounts near peaks and ridges. Winds could 
  gust as high as 35 MPH with localized blowing snow, especially 
  as you increase in elevation.

* WHERE...Portions of the Idaho central mountains, including but 
  not limited to the Frank Church Wilderness, Banner Summit, 
  Sawtooth Mountains, Galena Summit, the Big Lost Highlands, and 
  Lost River Range.

* WHEN...From noon Sunday to noon MDT Monday.

* IMPACTS...While slick conditions and light accumulations may
  occur down into Stanley, Ketchum, and Sun Valley during this
  event, the greatest concern for very difficult travel will exist
  over Galena Summit, as well as for local and backcountry roads
  above about 7,000 feet. In addition, the heavy, wet nature of
  the snow may strain weaker structures and tree limbs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, leave extra time and bring a flashlight, 
food, and water in your vehicle in case of an emergency.

The latest road conditions can be obtained by calling 5 1 1.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/pocatello
380 
WWUS45 KPIH 242034
WSWPIH

URGENT - WINTER WEATHER MESSAGE
National Weather Service Pocatello ID
234 PM MDT Sun Oct 24 2021

IDZ069-071>074-251300-
/O.CON.KPIH.WS.W.0007.000000T0000Z-211025T1800Z/
Lost River Range-Frank Church Wilderness-Sawtooth/Stanley Basin-
Sun Valley Region-Big Lost Highlands/Copper Basin-
Including the cities of Borah Peak, Clayton, Stanley, Ketchum, 
Sun Valley, Galena, and Copper Basin
234 PM MDT Sun Oct 24 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL NOON MDT MONDAY...

* WHAT...Heavy wet snow expected. Total snow accumulations of up 
  to 3 inches below 7000 feet with 3-12 inches above 7000 feet 
  and locally higher amounts near peaks and ridges. Winds could 
  gust as high as 35 MPH with localized blowing snow, especially 
  as you increase in elevation.

* WHERE...Portions of the Idaho central mountains, including but 
  not limited to the Frank Church Wilderness, Banner Summit, 
  Sawtooth Mountains, Galena Summit, the Big Lost Highlands, and 
  Lost River Range.

* WHEN...Through noon MDT Monday.

* IMPACTS...While slick conditions and light accumulations may 
  occur down into Stanley, Ketchum, and Sun Valley during this 
  event, the greatest concern for very difficult travel will 
  exist over Galena Summit, as well as for local and backcountry 
  roads above about 7,000 feet. In addition, the heavy, wet 
  nature of the snow may strain weaker structures and tree limbs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, leave extra time and bring a flashlight,
food, and water in your vehicle in case of an emergency.

The latest road conditions can be obtained by calling 5 1 1.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/pocatello
478 
WWUS45 KPIH 250908
WSWPIH

URGENT - WINTER WEATHER MESSAGE
National Weather Service Pocatello ID
308 AM MDT Mon Oct 25 2021

IDZ069-071>074-251800-
/O.CON.KPIH.WS.W.0007.000000T0000Z-211025T1800Z/
Lost River Range-Frank Church Wilderness-Sawtooth/Stanley Basin-
Sun Valley Region-Big Lost Highlands/Copper Basin-
Including the cities of Borah Peak, Clayton, Stanley, Ketchum, 
Sun Valley, Galena, and Copper Basin
308 AM MDT Mon Oct 25 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL NOON MDT TODAY...

* WHAT...Heavy wet snow expected. Total snow accumulations of up 
  to 3 inches below 7000 feet with 3-12 inches above 7000 feet 
  and locally higher amounts near peaks and ridges. Winds could 
  gust as high as 35 MPH with localized blowing snow, especially 
  as you increase in elevation.

* WHERE...Portions of the Idaho central mountains, including but 
  not limited to the Frank Church Wilderness, Banner Summit, 
  Sawtooth Mountains, Galena Summit, the Big Lost Highlands, and 
  Lost River Range.

* WHEN...Through noon MDT Monday.

* IMPACTS...While slick conditions and light accumulations may 
  occur down into Stanley, Ketchum, and Sun Valley during this 
  event, the greatest concern for very difficult travel will 
  exist over Galena Summit, as well as for local and backcountry 
  roads above about 7,000 feet. In addition, the heavy, wet 
  nature of the snow may strain weaker structures and tree limbs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, leave extra time and bring a flashlight,
food, and water in your vehicle in case of an emergency.

The latest road conditions can be obtained by calling 5 1 1.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/pocatello

Nearby

Winter Storm Warnings in Idaho, 2021Every winter storm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.