Alert archive / Idaho / Flash Flood Warnings in 2021

Flash Flood Warning 16, NWS Pocatello, ID

July 31, 2021Cassia County, Idaho

NWS Pocatello, ID issued this flash flood warning at Jul 31, 2021, 7:07 PM MDT for Cassia County, Idaho. It was in force for 3 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 31, 2021, 7:07 PM MDT (01:07 UTC)
Expired
Jul 31, 2021, 10:30 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 01:11 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.

What was reported inside it

TimeReportWhereRemark
Jul 31, 8:00 PM MDTFLASH FLOOD18 Wsw Oakley, IDUSFS REPORTED TRAPPER CREEK ROAD (533) WASHED OUT IN THE AREA OF FS ROAD 538 TO TROUT CREEK PASS. USFS OFFICIALS REPORTED A 12 FOOT DEEP GULLY RUNNING DOWN THE CENTER OF THE ROAD. THIS IS DUE TO EXCESSIVE RUNOFF FROM THE BURNED CANYON WALLS FROM THE BADGER BUR
Jul 31, 9:09 PM MDTHEAVY RAIN 0.617 Wsw Marion, IDMESONET STATION CRII1 - COTTON RIDGE. SINCE 409 PM.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Elko, NV (KLKN), launched 00:00Z, 1.1 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-pSkew-T log-p diagram, Elko, NV at 00:00Z on 2021-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 84 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, Elko, NV at 00:00Z on 2021-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -45 square meters per square second.1939Sfc1 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
84 J/kg
Mixed-layer CIN
-93 J/kg
Mixed-layer LCL
1100 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
-45 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

646 
WGUS55 KPIH 010107
FFWPIH
IDC031-010200-
/O.NEW.KPIH.FF.W.0016.210801T0107Z-210801T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pocatello ID
707 PM MDT Sat Jul 31 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 800 PM MDT.

* At 707 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain moving into the Badger Fire Burn Area. The expected 
  rainfall rate is 0.25 to 0.75 inches in 1 hour. 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
EXPECTED RAINFALL...0.25-0.75 INCHES IN 1 HOUR

$$

JKeyes
2 follow-up statements
883 
WGUS55 KPIH 010142
FFWPIH
IDC031-010430-
/O.EXT.KPIH.FF.W.0016.000000T0000Z-210801T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pocatello ID
742 PM MDT Sat Jul 31 2021

The National Weather Service in Pocatello has extended the

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

* Until 1030 PM MDT.

* At 742 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain over the Badger Fire Burn Area. Between 0.5 and 1 inch 
  of rain has fallen so far over southern portions of the burn scar. 
  The expected rainfall rate is 0.25 to 0.75 inches per 1 hour. 
  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.

This includes the following streams and drainages...
  Willow Creek, West Fork Thoroughbred Creek, Dry Fork, Dry Creek, 
  West Fork Dry Creek, East Fork Thoroughbred Creek, First Fork Rock 
  Creek, Trapper Creek, Cold Spring Creek, East Fork Dry Creek, 
  Trout Creek, Left Hand Fork Beaverdam Creek, Harrington Fork, 
  South Fork Little Piney Creek, Rock Creek, Little Goose Creek, 
  South Cottonwood Creek, Sawmill Creek, Medley Creek, Goose Creek, 
  Middle Fork Dry Creek, Fall Creek, Second Fork Rock Creek, Big 
  Cottonwood Creek, Little Squaw Creek, Cabin Spring Creek, Badger 
  Creek, Rodeo Creek, Third Fork Rock Creek, Little Fork Third Fork 
  Rock Creek, Wooden Shoe Creek, Little Cottonwood Creek, Beaverdam 
  Creek, Little Piney Creek, Billys Hole Creek and Coyote Creek.

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
EXPECTED RAINFALL...0.25-0.75 INCHES IN 1 HOUR

$$

KSmith
601 
WGUS75 KPIH 010428
FFSPIH

Flash Flood Statement
National Weather Service Pocatello ID
1028 PM MDT Sat Jul 31 2021

IDC031-010438-
/O.EXP.KPIH.FF.W.0016.000000T0000Z-210801T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cassia ID-
1028 PM MDT Sat Jul 31 2021

...THE FLASH FLOOD WARNING FOR THE BADGER FIRE BURN AREA WILL EXPIRE 
AT 1030 PM MDT THIS EVENING 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.

A Flash Flood Watch remains in effect until 900 PM MDT Monday for 
portions of eastern Idaho and southeast Idaho.

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

$$

KSmith

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 2:01 PM MDTFlash Flood WarningPIHPower3 hr
Aug 1, 2:06 PM MDTAreal Flood AdvisoryPIHCassia, Minidoka114 min
Aug 1, 2:21 PM MDTFlash Flood WarningPIHCassia3 hr
Aug 1, 3:04 PM MDTAreal Flood AdvisoryPIHBear Lake, Franklin116 min
Aug 1, 3:09 PM MDTAreal Flood AdvisoryPIHCassia111 min
Aug 1, 3:47 PM MDTFlash Flood WarningPIHBlaine3 hr
Aug 1, 3:51 PM MDTAreal Flood AdvisoryPIHBannock, Caribou, Franklin114 min
Aug 1, 4:01 PM MDTAreal Flood AdvisoryPIHBingham, Caribou119 min
Aug 1, 4:21 PM MDTAreal Flood AdvisoryPIHBlaine114 min
Aug 1, 4:55 PM MDTSpecial Weather StatementPIHBlaine50 min
Aug 1, 5:05 PM MDTAreal Flood AdvisoryPIHBlaine, Butte115 min
Aug 1, 5:09 PM MDTAreal Flood AdvisoryPIHCassia2 hr
Aug 1, 5:25 PM MDTSpecial Weather StatementPIHPower50 min
Aug 1, 5:36 PM MDTAreal Flood AdvisoryPIHPower114 min

Nearby

Flash Flood Warnings in Idaho, 2021Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.