Alert archive / Idaho / Snow Squall Warnings in 2021

Snow Squall Warning 4, NWS Pocatello, ID

December 26, 202113 counties in Idaho

NWS Pocatello, ID issued this snow squall warning at Dec 26, 2021, 12:40 PM MST for 13 counties in Idaho. It was in force for 50 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Dec 26, 2021, 12:40 PM MST (19:40 UTC)
Expired: Dec 26, 2021, 1:30 PM MST
In force: 50 min
Issued by: NWS Pocatello, ID
Area: Storm-based polygon

Counties Bannock County, ID, Bear Lake County, ID, Bingham County, ID, Bonneville County, ID, Butte County, ID, Caribou County, ID, Franklin County, ID, Fremont County, ID, Jefferson County, ID, Madison County, ID, Oneida County, ID, Power County, ID, Teton County, ID

The radar

The Pocatello radar (KSFX), 77 km from the middle of the area, began a volume at 19:44 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

Salt Lake City I, UT (KSLC), launched 12:00Z, 7.7 hours before the alert went out and 229 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1198 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 356 m²/s²
0-3 km storm-relative helicity: 385 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted.

491 
WWUS55 KPIH 261940
SQWPIH

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Snow Squall Warning
National Weather Service Pocatello ID
1240 PM MST Sun Dec 26 2021

IDC005-007-011-019-023-029-041-043-051-065-071-077-081-262030-
/O.NEW.KPIH.SQ.W.0004.211226T1940Z-211226T2030Z/
Fremont ID-Jefferson ID-Bingham ID-Teton ID-Caribou ID-Oneida ID-
Bannock ID-Butte ID-Power ID-Bonneville ID-Madison ID-Franklin ID-
Bear Lake ID-
1240 PM MST Sun Dec 26 2021

The National Weather Service in Pocatello has issued a

* Snow Squall Warning for...
  South central Fremont County in southeastern Idaho...
  Southeastern Jefferson County in southeastern Idaho...
  Bingham County in southeastern Idaho...
  Southwestern Teton County in eastern Idaho...
  Caribou County in southeastern Idaho...
  Oneida County in southeastern Idaho...
  Bannock County in southeastern Idaho...
  Southeastern Butte County in southeastern Idaho...
  Eastern Power County in southeastern Idaho...
  Bonneville County in southeastern Idaho...
  Madison County in southeastern Idaho...
  Franklin County in southeastern Idaho...
  Western Bear Lake County in southeastern Idaho...

* Until 130 PM MST.

* At 1234 PM MST, a dangerous snow squall was located along a line
  extending from 11 miles south of Terreton to 11 miles southwest of
  Bone to 6 miles south of Chesterfield to Holbrook Summit, moving
  east at 40 mph.

  HAZARD...Near whiteout conditions. One quarter mile visibility or 
           less in snow and blowing snow. Wind gusts exceeding 45 
           mph at times.

  SOURCE...Radar indicated and area webcams.

  IMPACT...Dangerous life-threatening travel.

* This will impact Interstate 15 from near Roberts south to Malad 
  City, U-S Highways 20 and 26 from the Arco Desert into the eastern 
  highlands, U-S 30 from Pocatello to Bear Lake, U-S 89 through the 
  Bear Lake area, U-S 91 from Idaho Falls through Pocatello to 
  Preston. This will also impact numerous state highways east of 
  Interstate 15. 

Locations impacted include...
Idaho Falls, Pocatello, Rexburg, Blackfoot, Preston, Rigby, Soda
Springs, Malad, McCammon, Lava Hot Springs, Swan Valley, Swanlake,
Ririe Reservoir, Blackfoot Reservoir, Lorenzo, Chesterfield 
Reservoir, Goshen, Wayan, and Palisades Reservoir.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Consider avoiding or delaying travel until the snow squall passes
your location. If you must travel, use extra caution and allow extra
time. Rapid changes in visibility and slick road conditions may lead
to accidents.

Reduce your speed and turn on headlights! During snow squalls, the
visibility may suddenly drop to near zero in whiteout conditions.

Slow Down! Rapid changes in visibility and road conditions are
expected with this dangerous snow squall. Be alert for sudden
whiteout conditions.

&&

LAT...LON 4211 11145 4210 11292 4259 11263 4360 11271
      4397 11129 4347 11104 4279 11104
TIME...MOT...LOC 1934Z 253DEG 35KT 4367 11235 4317 11191 4277 11187
4218 11262

$$

Keyes

2 follow-up statements

172 
WWUS55 KPIH 262010
SQWPIH

Snow Squall Warning
National Weather Service Pocatello ID
110 PM MST Sun Dec 26 2021

IDC023-262017-
/O.CAN.KPIH.SQ.W.0004.000000T0000Z-211226T2030Z/
Butte ID-
110 PM MST Sun Dec 26 2021

...THE SNOW SQUALL WARNING FOR SOUTHEASTERN BUTTE COUNTY IS
CANCELLED...

The snow squall which prompted the warning has moved out of the 
warned area.  Therefore, the snow squall warning has been cancelled. 
Gusty winds and some blowing snow will persist through the rest of 
the afternoon.

LAT...LON 4211 11145 4211 11283 4270 11254 4362 11245
      4397 11129 4347 11104 4279 11104
TIME...MOT...LOC 2007Z 253DEG 35KT 4375 11198 4325 11155 4285 11151
4226 11226

$$

IDC005-007-011-019-029-041-043-051-065-071-077-081-262030-
/O.CON.KPIH.SQ.W.0004.000000T0000Z-211226T2030Z/
Teton ID-Caribou ID-Fremont ID-Oneida ID-Jefferson ID-Bannock ID-
Power ID-Bonneville ID-Madison ID-Franklin ID-Bear Lake ID-
Bingham ID-
110 PM MST Sun Dec 26 2021

...A SNOW SQUALL WARNING REMAINS IN EFFECT UNTIL 130 PM MST FOR
SOUTHWESTERN TETON...CARIBOU...SOUTH CENTRAL FREMONT...CENTRAL
ONEIDA...SOUTHEASTERN JEFFERSON...BANNOCK...SOUTHEASTERN POWER...
BONNEVILLE...MADISON...FRANKLIN...WESTERN BEAR LAKE AND SOUTHEASTERN
BINGHAM COUNTIES...

At 107 PM MST, a dangerous snow squall was located along a line
extending from near Menan to 13 miles east of Bone to near Henry to
near Holbrook, moving east at 40 mph.

HAZARD...Extremely poor visibility in snow and blowing snow. Wind 
         gusts greater than 45 mph at times.

SOURCE...Radar and webcams.

IMPACT...Dangerous life-threatening travel.

This will impact Interstate 15 from near Roberts south to Malad 
City, U-S Highways 20 and 26 from INL into the eastern highlands, U-
S 30 from Pocatello to Bear Lake, U-S 89 through the Bear Lake area, 
U-S 91 from Idaho Falls through Pocatello to Preston. This will also 
impact numerous state highways east of Interstate 15. 

Locations impacted include...
Idaho Falls, Pocatello, Rexburg, Blackfoot, Preston, Rigby, Soda 
Springs, Malad, McCammon, Lava Hot Springs, Swan Valley, Ririe, 
Chesterfield, Blackfoot Reservoir, Wayan, and Palisades Reservoir.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Consider avoiding or delaying travel until the snow squall passes
your location. If you must travel, use extra caution and allow extra
time. Rapid changes in visibility and slick road conditions may lead
to accidents.

&&

LAT...LON 4211 11145 4211 11283 4270 11254 4362 11245
      4397 11129 4347 11104 4279 11104
TIME...MOT...LOC 2007Z 253DEG 35KT 4375 11198 4325 11155 4285 11151
4226 11226

$$

Keyes

845 
WWUS55 KPIH 262036
SQWPIH

Snow Squall Warning
National Weather Service Pocatello ID
136 PM MST Sun Dec 26 2021

IDC005-007-011-019-029-041-043-051-065-071-077-081-262044-
/O.EXP.KPIH.SQ.W.0004.000000T0000Z-211226T2030Z/
Teton ID-Caribou ID-Fremont ID-Oneida ID-Jefferson ID-Bannock ID-
Power ID-Bonneville ID-Madison ID-Franklin ID-Bear Lake ID-
Bingham ID-
136 PM MST Sun Dec 26 2021

...THE SNOW SQUALL WARNING FOR SOUTHWESTERN TETON...CARIBOU...SOUTH
CENTRAL FREMONT...CENTRAL ONEIDA...SOUTHEASTERN JEFFERSON...
BANNOCK...SOUTHEASTERN POWER...BONNEVILLE...MADISON...FRANKLIN...
WESTERN BEAR LAKE AND SOUTHEASTERN BINGHAM COUNTIES HAS EXPIRED...

The snow squall which prompted the warning has exited the area.
Therefore, this snow squall warning has been allowed to expire. 
Another Snow Squall Warning has been issued for areas farther east. 
Areas of blowing snow and snow-covered roads will continue to make 
travel difficult.

LAT...LON 4211 11145 4211 11283 4270 11254 4362 11245
      4397 11129 4347 11104 4279 11104
TIME...MOT...LOC 2034Z 253DEG 35KT 4382 11168 4332 11125 4292 11121
4233 11196

$$

Keyes

The office that day

Everything else NWS Pocatello, ID issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 26, 3:59 AM MST	Snow Squall Warning	PIH	Bingham, Blaine, Cassia, Minidoka, Power	61 min
Dec 26, 11:59 AM MST	Special Weather Statement	PIH	Bannock, Bingham, Bonneville, Caribou, Franklin, Jefferson and 3 more	76 min
Dec 26, 1:34 PM MST	Snow Squall Warning	PIH	Bannock, Bear Lake, Bingham, Bonneville, Caribou, Franklin and 3 more	26 min

Nearby

Snow Squall Warnings in Idaho, 2021 Every snow squall 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.