Alert archive / Idaho / Flash Flood Warnings in 2021

Flash Flood Warning 22, NWS Pocatello, ID

October 7, 2021Cassia County, Idaho

NWS Pocatello, ID issued this flash flood warning at Oct 7, 2021, 2:40 PM MDT for Cassia County, Idaho. It was in force for 2 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: Oct 7, 2021, 2:40 PM MDT (20:40 UTC)
Expired: Oct 7, 2021, 4:45 PM MDT
In force: 2 hr
Issued by: NWS Pocatello, ID
Area: Storm-based polygon
Flood severity: None

County Cassia County, ID

The radar

The Pocatello radar (KSFX), 157 km from the middle of the area, began a volume at 20:41 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, 8.7 hours before the alert went out and 155 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: 3 J/kg
Mixed-layer CIN: -60 J/kg
Mixed-layer LCL: 927 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: -9 m²/s²
0-3 km storm-relative helicity: 134 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

874 
WGUS55 KPIH 072040
FFWPIH
IDC031-072245-
/O.NEW.KPIH.FF.W.0022.211007T2040Z-211007T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pocatello ID
240 PM MDT Thu Oct 7 2021

The National Weather Service in Pocatello has issued a

* Flash Flood Warning for...
  West Central Cassia County in southeastern Idaho...

* Until 445 PM MDT.

* At 240 PM MDT, Doppler radar indicated a strong thunderstorm 
  producing heavy rain across the warned area. The expected rainfall 
  rate is 0.5 to 1 inch 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 Badger Fire. The debris flow can consist of rock, 
mud, vegetation and other loose materials.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4234 11429 4236 11419 4219 11404 4218 11408
      4213 11426 4218 11428 4233 11428 4233 11429

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...0.5-1 INCH IN 1 HOUR

$$

TW

1 follow-up statement

773 
WGUS75 KPIH 072248
FFSPIH

Flash Flood Statement
National Weather Service Pocatello ID
448 PM MDT Thu Oct 7 2021

IDC031-072258-
/O.EXP.KPIH.FF.W.0022.000000T0000Z-211007T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cassia ID-
448 PM MDT Thu Oct 7 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR WEST CENTRAL 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 1100 PM MDT Friday for 
the Badger Fire Burn Scar area.

LAT...LON 4234 11429 4236 11419 4219 11404 4218 11408
      4213 11426 4218 11428 4233 11428 4233 11429

$$

JKeyes

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 7, 1:36 PM MDT	Special Weather Statement	PIH	Bannock	24 min
Oct 7, 2:02 PM MDT	Special Weather Statement	PIH	Bannock	28 min
Oct 7, 2:04 PM MDT	Flash Flood Watch	PIH	Bear Lake, Caribou, Cassia, Franklin, Oneida	33 hr
Oct 7, 2:35 PM MDT	Severe Thunderstorm Warning	PIH	Cassia	25 min
Oct 7, 3:00 PM MDT	Special Weather Statement	PIH	Cassia	45 min
Oct 7, 3:54 PM MDT	Severe Thunderstorm Warning	PIH	Cassia	51 min
Oct 7, 4:41 PM MDT	Severe Thunderstorm Warning	PIH	Cassia, Power	34 min
Oct 7, 5:14 PM MDT	Severe Thunderstorm Warning	PIH	Cassia, Power	31 min
Oct 7, 5:44 PM MDT	Special Weather Statement	PIH	Power	31 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.