Alert archive / Idaho / Flash Flood Warnings in 2021

Flash Flood Warning 2, NWS Pocatello, ID

July 27, 2021Cassia County, Idaho

NWS Pocatello, ID issued this flash flood warning at Jul 27, 2021, 3:05 PM MDT for Cassia County, Idaho. It was in force for 3 hr. 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 27, 2021, 3:05 PM MDT (21:05 UTC)
Expired: Jul 27, 2021, 5:39 PM MDT
In force: 3 hr
Issued by: NWS Pocatello, ID
Area: Storm-based polygon
Flood severity: None

County Cassia County, ID

The radar

The Pocatello radar (KSFX), 151 km from the middle of the area, began a volume at 21:08 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

Elko, NV (KLKN), launched 12:00Z, 9.1 hours before the alert went out and 151 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: 2215 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: -18 m²/s²
0-3 km storm-relative helicity: 38 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

873 
WGUS55 KPIH 272105
FFWPIH
IDC031-280000-
/O.NEW.KPIH.FF.W.0002.210727T2105Z-210728T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pocatello ID
305 PM MDT Tue Jul 27 2021

The National Weather Service in Pocatello has issued a

* Flash Flood Warning for...
  The Badger Fire Burn Area in...
  Southwestern Cassia County in southeastern Idaho...

* Until 600 PM MDT.

* At 305 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain over the Badger Fire Burn Area. Flash flooding is 
  ongoing or expected to begin shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through the Rock Creek...Dry Creek...Big Cottonwood Creek...
and Trapper Creek. The debris flow can consist of rock, mud, 
vegetation and other loose materials.

  HAZARD...Flash flooding caused by thunderstorms in and around
           the Badger Fire Burn Area.

  SOURCE...Radar.

  IMPACT...Flooding of areas in and around the Badger Fire Burn
           Area.

* Some locations that will experience flash flooding include...
  Oakley Reservoir and Bostetter Ranger Station.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life threatening situation.  Heavy rainfall may cause 
extensive and severe flash flooding of creeks and streams in the 
Badger Fire Burn Area.  Some drainage basins impacted include Rock 
Creek...Dry Creek...Big Cottonwood Creek...and Trapper Creek.  
Severe debris flows can also be anticipated across roads.  Roads and 
driveways may be washed away in places.  If you encounter flood 
waters...climb to safety.

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 4242 11429 4242 11416 4229 11413 4226 11408
      4228 11405 4227 11402 4222 11405 4218 11400
      4220 11395 4219 11392 4217 11394 4212 11403
      4206 11408 4204 11412 4204 11428

FLASH FLOOD...RADAR INDICATED

$$

LC

1 follow-up statement

128 
WGUS75 KPIH 272339
FFSPIH

Flash Flood Statement
National Weather Service Pocatello ID
539 PM MDT Tue Jul 27 2021

IDC031-272349-
/O.CAN.KPIH.FF.W.0002.000000T0000Z-210728T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cassia ID-
539 PM MDT Tue Jul 27 2021

...FLASH FLOOD WARNING FOR THE BADGER FIRE BURN AREA IS CANCELLED 
FOR SOUTHWESTERN CASSIA COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures. Additional 
thunderstorms are expected through the evening.

LAT...LON 4242 11429 4242 11416 4229 11413 4226 11408
      4228 11405 4227 11402 4222 11405 4218 11400
      4220 11395 4219 11392 4217 11394 4212 11403
      4206 11408 4204 11412 4204 11428

$$

DH

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 27, 2:05 AM MDT	Red Flag Warning	PIH	Custer, Idaho, Lemhi, Valley	20 hr
Jul 27, 3:31 PM MDT	Special Weather Statement	PIH	Bear Lake	44 min
Jul 27, 4:12 PM MDT	Special Weather Statement	PIH	Bear Lake	48 min
Jul 27, 4:32 PM MDT	Flash Flood Warning	PIH	Bear Lake, Franklin	115 min

Nearby

Flash Flood Warnings in Idaho, 2021 Every flash flood 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.