Alert archive / Idaho / Flash Flood Warnings in 2021

Flash Flood Warning 10, NWS Pocatello, ID

July 30, 2021Power County, Idaho

NWS Pocatello, ID issued this flash flood warning at Jul 30, 2021, 2:45 PM MDT for Power County, Idaho. It was in force for 90 min. 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, 2:45 PM MDT (20:45 UTC)
Expired: Jul 30, 2021, 4:15 PM MDT
In force: 90 min
Issued by: NWS Pocatello, ID
Area: Storm-based polygon
Flood severity: None

County Power County, ID

The radar

The Pocatello radar (KSFX), 67 km from the middle of the area, began a volume at 20:47 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	2 S Rockland, ID	AN NWS SURVEY FOUND SEVERAL WASHOUTS ALONG HIGHWAY 37 SOUTH OF ROCKLAND INCLUDING ONE ALONG KING LANE. TIME ESTIMATED VIA RADAR.

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, 8.8 hours before the alert went out and 212 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.

428 
WGUS55 KPIH 302045
FFWPIH
IDC077-302215-
/O.NEW.KPIH.FF.W.0010.210730T2045Z-210730T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Pocatello ID
245 PM MDT Fri Jul 30 2021

The National Weather Service in Pocatello has issued a

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

* Until 415 PM MDT.

* At 245 PM MDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1.5 and 2 inches of 
  rain have fallen. 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...
  mainly rural areas of South Central Power County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4259 11294 4255 11286 4244 11287 4242 11299
      4257 11299

FLASH FLOOD...RADAR INDICATED

$$

DV

1 follow-up statement

841 
WGUS75 KPIH 302211
FFSPIH

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

IDC077-302221-
/O.EXP.KPIH.FF.W.0010.000000T0000Z-210730T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Power ID-
411 PM MDT Fri Jul 30 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 415 PM MDT THIS AFTERNOON FOR 
SOUTH CENTRAL POWER 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 4259 11294 4255 11286 4244 11287 4242 11299
      4257 11299

$$

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, 2:38 PM MDT	Flash Flood Warning	PIH	Cassia	3 hr
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.