Alert archive / Idaho / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 17, NWS Pocatello, ID

September 2, 2021Caribou County, Idaho

NWS Pocatello, ID issued this severe thunderstorm warning at Sep 2, 2021, 8:43 PM MDT for Caribou County, Idaho. It was in force for 32 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
Sep 2, 2021, 8:43 PM MDT (02:43 UTC)
Expired
Sep 2, 2021, 9:15 PM MDT
In force
32 min
Issued by
NWS Pocatello, ID
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
50.0 mph

County Caribou County, ID

The radar

The Pocatello radar (KSFX), 121 km from the middle of the area, began a volume at 02:43 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 00:00Z, 2.7 hours before the alert went out and 225 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, Salt Lake City I, UT at 00:00Z on 2021-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 942 joules per kilogram.LCLLFCEL10008507005003002001001 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, Salt Lake City I, UT at 00:00Z on 2021-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 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
942 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
2400 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

Open this sounding in Storm Lab

The text

As transmitted.

183 
WUUS55 KPIH 030243
SVRPIH
IDC029-030315-
/O.NEW.KPIH.SV.W.0017.210903T0243Z-210903T0315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Pocatello ID
843 PM MDT Thu Sep 2 2021

The National Weather Service in Pocatello has issued a

* Severe Thunderstorm Warning for...
  East central Caribou County in southeastern Idaho...

* Until 915 PM MDT.

* At 842 PM MDT, a severe thunderstorm was located 13 miles southeast
  of Henry, or 13 miles northeast of Soda Springs, moving east at 25
  MPH.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Diamond Creek Campground and Smokey Canyon Mine. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

If you observe severe weather, including hail or wind damage, please 
report your observations to the National Weather Service in 
Pocatello via phone at 208-233-0834, or via social media.

&&

LAT...LON 4266 11144 4285 11144 4293 11104 4265 11105
TIME...MOT...LOC 0242Z 262DEG 21KT 4275 11134 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

KSmith
2 follow-up statements
524 
WWUS55 KPIH 030258
SVSPIH

Severe Weather Statement
National Weather Service Pocatello ID
858 PM MDT Thu Sep 2 2021

IDC029-030315-
/O.CON.KPIH.SV.W.0017.000000T0000Z-210903T0315Z/
Caribou ID-
858 PM MDT Thu Sep 2 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM MDT
FOR EAST CENTRAL CARIBOU COUNTY...

At 857 PM MDT, a severe thunderstorm was located 14 miles southwest
of Star Valley Rest Area, or 14 miles west of Afton, moving east at
25 MPH.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Diamond Creek Campground and Smokey Canyon Mine. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

If you observe severe weather, including hail or wind damage, please 
report your observations to the National Weather Service in 
Pocatello via phone at 208-233-0834, or via social media.

&&

LAT...LON 4266 11132 4286 11134 4293 11104 4265 11105
TIME...MOT...LOC 0257Z 262DEG 21KT 4276 11122 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

KSmith
038 
WWUS55 KPIH 030316
SVSPIH

Severe Weather Statement
National Weather Service Pocatello ID
916 PM MDT Thu Sep 2 2021

IDC029-030325-
/O.EXP.KPIH.SV.W.0017.000000T0000Z-210903T0315Z/
Caribou ID-
916 PM MDT Thu Sep 2 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL CARIBOU COUNTY
HAS EXPIRED...
        
The storm which prompted the warning has weakened below severe 
limits, and has exited the warned area into Wyoming. Therefore, the 
warning has been allowed to expire.

If you observed severe weather, including hail or wind damage, 
please report your observations to the National Weather Service in 
Pocatello via phone at 208-233-0834, or via social media.

LAT...LON 4266 11132 4286 11134 4293 11104 4265 11105
TIME...MOT...LOC 0315Z 262DEG 21KT 4277 11108 

$$

KSmith

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 2, 7:18 PM MDTSpecial Weather StatementPIHCaribou42 min
Sep 2, 7:55 PM MDTSpecial Weather StatementPIHCaribou35 min
Sep 2, 8:20 PM MDTSevere Thunderstorm WarningPIHCaribou25 min

Nearby

Severe Thunderstorm Warnings in Idaho, 2021Every severe thunderstorm 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.