Alert archive / Idaho / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 21, NWS Pocatello, ID

September 12, 2021Bear Lake County, Caribou County, Idaho

NWS Pocatello, ID issued this severe thunderstorm warning at Sep 12, 2021, 6:17 PM MDT for Bear Lake County, Caribou County, Idaho. It was in force for 28 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 12, 2021, 6:17 PM MDT (00:17 UTC)
Expired
Sep 12, 2021, 6:45 PM MDT
In force
28 min
Issued by
NWS Pocatello, ID
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Bear Lake County, ID, Caribou County, ID

The radar

The Pocatello radar (KSFX), 136 km from the middle of the area, began a volume at 00:19 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, 0.3 hours before the alert went out and 202 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 2021-09-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 642 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 2021-09-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 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
642 J/kg
Mixed-layer CIN
-52 J/kg
Mixed-layer LCL
2449 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
123 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.0

Open this sounding in Storm Lab

The text

As transmitted.

483 
WUUS55 KPIH 130017
SVRPIH
IDC007-029-130045-
/O.NEW.KPIH.SV.W.0021.210913T0017Z-210913T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Pocatello ID
617 PM MDT Sun Sep 12 2021

The National Weather Service in Pocatello has issued a

* Severe Thunderstorm Warning for...
  Southeastern Caribou County in southeastern Idaho...
  Northeastern Bear Lake County in southeastern Idaho...

* Until 645 PM MDT.

* At 616 PM MDT, a severe thunderstorm was located 7 miles northeast
  of Georgetown, or 15 miles north of Montpelier, moving east at 25
  mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Clear Creek Ranger Station.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4244 11133 4262 11135 4267 11105 4243 11105
TIME...MOT...LOC 0016Z 264DEG 21KT 4254 11125 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DMH
1 follow-up statement
290 
WWUS55 KPIH 130045
SVSPIH

Severe Weather Statement
National Weather Service Pocatello ID
645 PM MDT Sun Sep 12 2021

IDC007-029-130055-
/O.EXP.KPIH.SV.W.0021.000000T0000Z-210913T0045Z/
Caribou ID-Bear Lake ID-
645 PM MDT Sun Sep 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN CARIBOU AND
NORTHEASTERN BEAR LAKE COUNTIES HAS EXPIRED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been allowed to expire.

LAT...LON 4244 11133 4262 11135 4267 11105 4243 11105
TIME...MOT...LOC 0045Z 264DEG 21KT 4256 11105 

$$

DMH

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 12, 6:32 PM MDTSpecial Weather StatementPIHOneida28 min
Sep 12, 7:11 PM MDTSpecial Weather StatementPIHCaribou34 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.