Alert archive / Idaho / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 8, NWS Pocatello, ID

July 15, 2021Bonneville County, Idaho

NWS Pocatello, ID issued this severe thunderstorm warning at Jul 15, 2021, 3:44 PM MDT for Bonneville County, Idaho. It was in force for 31 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: Jul 15, 2021, 3:44 PM MDT (21:44 UTC)
Expired: Jul 15, 2021, 4:15 PM MDT
In force: 31 min
Issued by: NWS Pocatello, ID
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Bonneville County, ID

The radar

The Pocatello radar (KSFX), 118 km from the middle of the area, began a volume at 21:45 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

Riverton, WY (KRIW), launched 12:00Z, 9.7 hours before the alert went out and 233 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: 345 J/kg
Mixed-layer CIN: -183 J/kg
Mixed-layer LCL: 1860 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: -31 m²/s²
0-3 km storm-relative helicity: 71 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

618 
WUUS55 KPIH 152144
SVRPIH
IDC019-152215-
/O.NEW.KPIH.SV.W.0008.210715T2144Z-210715T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Pocatello ID
344 PM MDT Thu Jul 15 2021

The National Weather Service in Pocatello has issued a

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

* Until 415 PM MDT.

* At 343 PM MDT, a severe thunderstorm was located near Irwin, or 7
  miles south of Swan Valley, moving east at 20 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...
  Swan Valley, Palisades Reservoir and Irwin. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

If on or near Palisades Reservoir, get away from the water and move 
indoors or inside a vehicle. Remember, lightning can strike out to 
15 miles from the parent thunderstorm. If you can hear thunder, you 
are close enough to be struck by lightning. Move to safe shelter 
now!  Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4325 11140 4343 11140 4346 11105 4321 11104
TIME...MOT...LOC 2143Z 266DEG 19KT 4333 11129 

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

$$

JKeyes

2 follow-up statements

156 
WWUS55 KPIH 152201
SVSPIH

Severe Weather Statement
National Weather Service Pocatello ID
401 PM MDT Thu Jul 15 2021

IDC019-152215-
/O.CON.KPIH.SV.W.0008.000000T0000Z-210715T2215Z/
Bonneville ID-
401 PM MDT Thu Jul 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM MDT
FOR EAST CENTRAL BONNEVILLE COUNTY...

At 400 PM MDT, a severe thunderstorms was extending from Irwin to 
over Palisades Reservoir, moving east at 20 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...
Swan Valley, northern Palisades Reservoir and Irwin. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

If on or near Palisades Reservoir, get away from the water and move 
indoors or inside a vehicle. remember, lightning can strike out to 
15 miles from the parent thunderstorm. If you can hear thunder, you 
are close enough to be struck by lightning. Move to safe shelter 
now!  Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4325 11140 4343 11140 4346 11105 4321 11104
TIME...MOT...LOC 2200Z 266DEG 19KT 4334 11116 

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

$$

JKeyes

281 
WWUS55 KPIH 152211
SVSPIH

Severe Weather Statement
National Weather Service Pocatello ID
411 PM MDT Thu Jul 15 2021

IDC019-152220-
/O.EXP.KPIH.SV.W.0008.000000T0000Z-210715T2215Z/
Bonneville ID-
411 PM MDT Thu Jul 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL BONNEVILLE COUNTY
WILL EXPIRE AT 415 PM MDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However small 
hail, gusty winds and locally heavy rain are still possible with 
this thunderstorm.

LAT...LON 4325 11140 4343 11140 4346 11105 4321 11104
TIME...MOT...LOC 2210Z 266DEG 19KT 4334 11112 

$$

JKeyes

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 15, 1:09 PM MDT	Red Flag Warning	PIH	Blaine, Boise, Custer, Idaho, Lemhi, Valley	38 hr
Jul 15, 5:14 PM MDT	Special Weather Statement	PIH	Bear Lake, Franklin	61 min

Nearby

Severe Thunderstorm Warnings in Idaho, 2021 Every 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.