Alert archive / Idaho / Flash Flood Warnings in 2021

Flash Flood Warning 9, NWS Pocatello, ID

July 30, 2021Cassia County, Idaho

NWS Pocatello, ID issued this flash flood warning at Jul 30, 2021, 2:38 PM MDT for Cassia County, Idaho. It was in force for 3 hr. 1 report 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 30, 2021, 2:38 PM MDT (20:38 UTC)
Expired: Jul 30, 2021, 5:30 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 20:38 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

Time	Report	Where	Remark
Jul 30, 3:30 PM MDT	FLASH FLOOD	12 Sw Oakley, ID	FLOODING OBSERVED ALONG TRAPPER CREEK ROAD WITH EXCESSIVE RUNOFF FROM THE SQUAW CREEK AND LITTLE SQUAW CREEK DRAINAGES. THIS LED TO SEVERAL INCHES OF ROCKS, MUD AND DEBRIS OVER THE ROADWAY. INFORMATION GAINED BY NWS SURVEY DISCUSSING WITH LOCAL LAND OWNER.

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 12:00Z, 8.6 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: 10 J/kg
Mixed-layer CIN: -189 J/kg
Mixed-layer LCL: 1966 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 15 m²/s²
0-3 km storm-relative helicity: -39 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

762 
WGUS55 KPIH 302038
FFWPIH
IDC031-302330-
/O.NEW.KPIH.FF.W.0009.210730T2038Z-210730T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pocatello ID
238 PM MDT Fri Jul 30 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 530 PM MDT.

* At 238 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 Trapper Creek, South Cottonwood Creek, and Badger 
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

$$

JK

1 follow-up statement

145 
WGUS75 KPIH 302326
FFSPIH

Flash Flood Statement
National Weather Service Pocatello ID
526 PM MDT Fri Jul 30 2021

IDC031-302336-
/O.EXP.KPIH.FF.W.0009.000000T0000Z-210730T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cassia ID-
526 PM MDT Fri Jul 30 2021

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

$$

DV

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 5:25 AM MDT	Special Weather Statement	PIH	Bear Lake	50 min
Jul 30, 12:50 PM MDT	Areal Flood Advisory	PIH	Bannock	22 min
Jul 30, 12:55 PM MDT	Flash Flood Watch	PIH	Bannock, Bear Lake, Bingham, Blaine, Bonneville, Butte and 10 more	3 days
Jul 30, 1:12 PM MDT	Flash Flood Warning	PIH	Bannock	108 min
Jul 30, 1:50 PM MDT	Flash Flood Warning	PIH	Bannock, Power	115 min
Jul 30, 1:55 PM MDT	Areal Flood Advisory	PIH	Power	2 hr
Jul 30, 1:57 PM MDT	Flash Flood Warning	PIH	Oneida	2 hr
Jul 30, 2:19 PM MDT	Areal Flood Advisory	PIH	Power	26 min
Jul 30, 2:24 PM MDT	Areal Flood Advisory	PIH	Bannock	81 min
Jul 30, 2:45 PM MDT	Flash Flood Warning	PIH	Power	90 min
Jul 30, 3:02 PM MDT	Flash Flood Warning	PIH	Cassia	3 hr
Jul 30, 3:09 PM MDT	Special Weather Statement	PIH	Cassia	51 min
Jul 30, 3:48 PM MDT	Areal Flood Advisory	PIH	Bonneville	117 min
Jul 30, 5:17 PM MDT	Areal Flood Advisory	PIH	Blaine	118 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.