Alert archive / Idaho / Flash Flood Warnings in 2021

Flash Flood Warning 2, NWS Spokane, WA

August 1, 2021Shoshone County, Idaho

NWS Spokane, WA issued this flash flood warning at Aug 1, 2021, 6:23 PM PDT for Shoshone 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, 6:23 PM PDT (01:23 UTC)
Expired: Aug 1, 2021, 9:30 PM PDT
In force: 3 hr
Issued by: NWS Spokane, WA
Area: Storm-based polygon
Flood severity: None

County Shoshone County, ID

The radar

The Missoula radar (KMSX), 112 km from the middle of the area, began a volume at 01:27 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

Spokane, WA (KOTX), launched 00:00Z, 1.4 hours before the alert went out and 91 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1384 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: -16 m²/s²
0-3 km storm-relative helicity: 23 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

857 
WGUS56 KOTX 020123
FFWOTX
IDC079-020430-
/O.NEW.KOTX.FF.W.0002.210802T0123Z-210802T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Spokane WA
623 PM PDT Sun Aug 1 2021

The National Weather Service in Spokane has issued a

* Flash Flood Warning for...
  The burn scar in...
  Southeastern Shoshone County in the panhandle of Idaho...

* Until 930 PM PDT.

* At 623 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain over the burn scar. Up to 0.5 inches of rain have 
  fallen. Flash flooding is ongoing or expected to begin shortly.

Excessive rainfall over the burn scar will result in debris flow. 
The debris flow can consist of rock, mud, vegetation and other loose 
materials.

  HAZARD...Flash flooding caused by thunderstorms in and around
           the burn scar.

  SOURCE...Radar.

  IMPACT...Flooding of areas in and around the burn scar.

* Some locations that will experience flash flooding include...
  mainly rural areas of Southeastern Shoshone County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life threatening situation. Heavy rainfall will cause 
extensive and severe flash flooding of creeks...streams...and 
ditches in the Tumbledown Stateline Complex. 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.

Move away from recently burned areas. Life-threatening flooding of 
creeks, roads and normally dry arroyos is likely. The heavy rains 
will likely trigger rockslides, mudslides and debris flows in steep 
terrain, especially in and around these areas.

&&

LAT...LON 4720 11541 4716 11541 4717 11553 4721 11552

FLASH FLOOD...RADAR INDICATED

$$

vmt

1 follow-up statement

878 
WGUS76 KOTX 020424
FFSOTX

Flash Flood Statement
National Weather Service Spokane WA
924 PM PDT Sun Aug 1 2021

IDC079-020434-
/O.EXP.KOTX.FF.W.0002.000000T0000Z-210802T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Shoshone ID-
924 PM PDT Sun Aug 1 2021

...FLASH FLOOD WARNING FOR THE BURN SCAR WILL EXPIRE AT 930 PM PDT 
THIS EVENING FOR SOUTHEASTERN SHOSHONE COUNTY...

The Flash Flood Warning for the Tumbledown Stateline Complex burn 
scar has been allowed to expire. The potential for moderate to heavy 
rain still exists through late tonight.

A Flash Flood Watch remains in effect until 500 AM PDT Monday for 
Portions of North and North Central Idaho.

LAT...LON 4720 11541 4716 11541 4717 11553 4721 11552

$$

vmt

The office that day

Everything else NWS Spokane, WA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 1, 8:15 PM PDT	Areal Flood Advisory	OTX	Lewis	3 hr
Aug 2, 2:37 AM PDT	Excessive Heat Watch	OTX	Benewah, Bonner, Boundary, Kootenai, Latah, Lewis and 2 more	12 hr
Aug 2, 2:46 PM PDT	Heat Advisory	OTX	Benewah, Bonner, Boundary, Kootenai, Latah, Lewis and 2 more	56 hr

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.