Alert archive / Idaho / Flash Flood Warnings in 2021

Flash Flood Warning 17, NWS Pocatello, ID

August 1, 2021Power County, Idaho

NWS Pocatello, ID issued this flash flood warning at Aug 1, 2021, 2:01 PM MDT for Power 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: Aug 1, 2021, 2:01 PM MDT (20:01 UTC)
Expired: Aug 1, 2021, 5:00 PM MDT
In force: 3 hr
Issued by: NWS Pocatello, ID
Area: Storm-based polygon
Flood severity: None

County Power County, ID

The radar

The Pocatello radar (KSFX), 42 km from the middle of the area, began a volume at 20:01 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

Salt Lake City I, UT (KSLC), launched 12:00Z, 8.0 hours before the alert went out and 226 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: 1 J/kg
Mixed-layer CIN: -264 J/kg
Mixed-layer LCL: 1731 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: -11 m²/s²
0-3 km storm-relative helicity: 9 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

679 
WGUS55 KPIH 012001
FFWPIH
IDC077-012300-
/O.NEW.KPIH.FF.W.0017.210801T2001Z-210801T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pocatello ID
201 PM MDT Sun Aug 1 2021

The National Weather Service in Pocatello has issued a

* Flash Flood Warning for...
  Central Power County in southeastern Idaho...

* Until 500 PM MDT.

* At 201 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1 inch of rain 
  has fallen on already saturated ground. The expected rainfall rate 
  is 0.5 to 1 inch in 1 hour. Flash flooding is ongoing or expected 
  to begin shortly.

  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...
  Fort Hall Bannock Creek Lodge. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4267 11272 4267 11278 4283 11275 4284 11261
      4267 11260

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

$$

JKeyes

1 follow-up statement

391 
WGUS75 KPIH 012251
FFSPIH

Flash Flood Statement
National Weather Service Pocatello ID
451 PM MDT Sun Aug 1 2021

IDC077-012301-
/O.EXP.KPIH.FF.W.0017.000000T0000Z-210801T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Power ID-
451 PM MDT Sun Aug 1 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 5 PM MDT THIS AFTERNOON FOR 
CENTRAL POWER COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat.
A Flash Flood Watch remains in effect until 900 PM MDT Monday for 
portions of eastern Idaho and southeast Idaho.

LAT...LON 4267 11272 4267 11278 4283 11275 4284 11261
      4267 11260

$$

JKeyes

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 31, 7:07 PM MDT	Flash Flood Warning	PIH	Cassia	3 hr
Aug 1, 2:06 PM MDT	Areal Flood Advisory	PIH	Cassia, Minidoka	114 min
Aug 1, 2:21 PM MDT	Flash Flood Warning	PIH	Cassia	3 hr
Aug 1, 3:04 PM MDT	Areal Flood Advisory	PIH	Bear Lake, Franklin	116 min
Aug 1, 3:09 PM MDT	Areal Flood Advisory	PIH	Cassia	111 min
Aug 1, 3:47 PM MDT	Flash Flood Warning	PIH	Blaine	3 hr
Aug 1, 3:51 PM MDT	Areal Flood Advisory	PIH	Bannock, Caribou, Franklin	114 min
Aug 1, 4:01 PM MDT	Areal Flood Advisory	PIH	Bingham, Caribou	119 min
Aug 1, 4:21 PM MDT	Areal Flood Advisory	PIH	Blaine	114 min
Aug 1, 4:55 PM MDT	Special Weather Statement	PIH	Blaine	50 min
Aug 1, 5:05 PM MDT	Areal Flood Advisory	PIH	Blaine, Butte	115 min
Aug 1, 5:09 PM MDT	Areal Flood Advisory	PIH	Cassia	2 hr
Aug 1, 5:25 PM MDT	Special Weather Statement	PIH	Power	50 min
Aug 1, 5:36 PM MDT	Areal Flood Advisory	PIH	Power	114 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.