Alert archive / Idaho / Flash Flood Watches in 2021

Flash Flood Watch 3, NWS Spokane, WA

July 31, 2021Chelan County, Okanogan County, Washington; 5 counties in Idaho

NWS Spokane, WA issued this flash flood watch at Jul 31, 2021, 2:01 PM PDT for Chelan County, Okanogan County, Washington; 5 counties in Idaho. It took effect at Aug 1, 2021, 6:00 AM PDT. It was in force for 21 hr.

The area

The counties it named.

The facts

Issued
Jul 31, 2021, 2:01 PM PDT (21:01 UTC)
In effect from
Aug 1, 2021, 6:00 AM PDT
Expired
Aug 2, 2021, 2:46 AM PDT
In force
21 hr
Issued by
NWS Spokane, WA
Flood severity
None

Counties Benewah County, ID, Latah County, ID, Lewis County, ID, Nez Perce County, ID, Shoshone County, ID, Chelan County, WA, Okanogan County, WA

The radar

The Spokane radar (KOTX), 54 km from the middle of the area, began a volume at 21:05 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 12:00Z, 9.0 hours before the alert went out and 103 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-pSkew-T log-p diagram, Spokane, WA at 12:00Z on 2021-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Spokane, WA at 12:00Z on 2021-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
3394 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
36 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

440 
WGUS66 KOTX 312101
FFAOTX

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Spokane WA
201 PM PDT Sat Jul 31 2021

.Thunderstorms producing torrential rain may lead to flash flooding 
on Sunday especially over and near burn scars.

WAC007-047-011415-
/O.NEW.KOTX.FF.A.0003.210801T1300Z-210802T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chelan-Okanogan-
Including the cities of Omak, Winthrop, Manson, Brewster, Plain,
Leavenworth, Methow, Okanogan, Twisp, Mazama, Oroville, Cashmere,
Chelan, Conconully, Entiat, and Wenatchee
201 PM PDT Sat Jul 31 2021

...FLASH FLOOD WATCH IN EFFECT FROM SUNDAY MORNING THROUGH SUNDAY 
AFTERNOON...

The National Weather Service in Spokane has issued a

* Flash Flood Watch for A portion of North Central Washington, 
  including the following areas, Chelan and Okanogan.

* From Sunday morning through Sunday afternoon.

* Thunderstorms with torrential rain combined with steep terrain 
  and/or previously fire burned areas could result in dangerous 
  flash flooding.

* Sudden rushes of water in creek and stream drainages could wash 
  away any person or thing nearby. Debris flows can cause additional 
  damage to low lying bridges or other structures. Road washouts are 
  common in flash flood events.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

IDC009-057-061-069-079-011415-
/O.NEW.KOTX.FF.A.0003.210801T1900Z-210802T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Benewah-Latah-Lewis-Nez Perce-Shoshone-
Including the cities of Winchester, Osburn, Nezperce, Kamiah,
Juliaetta, St Maries, Wallace, Tensed, Moscow, Deary, Kellogg,
Calder, Peck, Mullan, Smelterville, Craigmont, Lapwai, Kendrick,
Culdesac, Lewiston, Potlatch, Plummer, Gifford, Genesee, and
Pinehurst
201 PM PDT Sat Jul 31 2021

...FLASH FLOOD WATCH IN EFFECT FROM SUNDAY AFTERNOON THROUGH LATE 
SUNDAY NIGHT...

The National Weather Service in Spokane has issued a

* Flash Flood Watch for Portions of North and North Central Idaho, 
  including the following areas, in North Idaho, Benewah, Latah and 
  Shoshone. In North Central Idaho, Lewis and Nez Perce.

* From Sunday afternoon through late Sunday night.

* Thunderstorms with torrential rain combined with steep terrain 
  and/or previously fire burned areas could result in dangerous 
  flash flooding.

* Sudden rushes of water in creek and stream drainages could wash 
  away any person or thing nearby. Debris flows can cause additional 
  damage to low lying bridges or other structures. Road washouts are 
  common in flash flood events

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

JW
3 follow-up statements
934 
WGUS66 KOTX 011246
FFAOTX

Flood Watch
National Weather Service Spokane WA
546 AM PDT Sun Aug 1 2021

.Thunderstorms producing torrential rain may lead to flash flooding 
on Sunday especially over and near burn scars.

WAC007-047-020000-
/O.CON.KOTX.FF.A.0003.210801T1300Z-210802T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chelan-Okanogan-
Including the cities of Omak, Winthrop, Manson, Brewster, Plain,
Leavenworth, Methow, Okanogan, Twisp, Mazama, Oroville, Cashmere,
Chelan, Conconully, Entiat, and Wenatchee
546 AM PDT Sun Aug 1 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 5 PM PDT THIS 
AFTERNOON...

The Flash Flood Watch continues for

* A portion of North Central Washington, including the following 
  areas, Chelan and Okanogan.

* Until 5 PM PDT this afternoon.

* Thunderstorms with torrential rain combined with steep terrain 
  and/or previously fire burned areas could result in dangerous 
  flash flooding.

* Sudden rushes of water in creek and stream drainages could wash 
  away any person or thing nearby. Debris flows can cause additional 
  damage to low lying bridges or other structures. Road washouts are 
  common in flash flood events.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

IDC009-057-061-069-079-020015-
/O.CON.KOTX.FF.A.0003.210801T1900Z-210802T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Benewah-Latah-Lewis-Nez Perce-Shoshone-
Including the cities of Winchester, Osburn, Nezperce, Kamiah,
Juliaetta, St Maries, Wallace, Tensed, Moscow, Deary, Kellogg,
Calder, Peck, Mullan, Smelterville, Craigmont, Lapwai, Kendrick,
Culdesac, Lewiston, Potlatch, Plummer, Gifford, Genesee, and
Pinehurst
546 AM PDT Sun Aug 1 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT FROM NOON PDT TODAY THROUGH 
LATE TONIGHT...

The Flash Flood Watch continues for

* Portions of North and North Central Idaho, including the following 
  areas, in North Idaho, Benewah, Latah and Shoshone. In North 
  Central Idaho, Lewis and Nez Perce.

* From Noon PDT today through late tonight.

* Thunderstorms with torrential rain combined with steep terrain 
  and/or previously fire burned areas could result in dangerous 
  flash flooding.

* Sudden rushes of water in creek and stream drainages could wash 
  away any person or thing nearby. Debris flows can cause additional 
  damage to low lying bridges or other structures. Road washouts are 
  common in flash flood events

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

JS
160 
WGUS66 KOTX 012248
FFAOTX

Flood Watch
National Weather Service Spokane WA
348 PM PDT Sun Aug 1 2021

WAC007-047-020000-
/O.CAN.KOTX.FF.A.0003.000000T0000Z-210802T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Chelan-Okanogan-
Including the cities of Omak, Winthrop, Manson, Brewster, Plain,
Leavenworth, Methow, Okanogan, Twisp, Mazama, Oroville, Cashmere,
Chelan, Conconully, Entiat, and Wenatchee
348 PM PDT Sun Aug 1 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for a portion of North Central Washington, 
including Chelan and Okanogan counties, has been cancelled.

The Flash Flood Watch is cancelled. Flooding is no longer expected 
to pose a threat.

$$

IDC009-057-061-069-079-021200-
/O.CON.KOTX.FF.A.0003.000000T0000Z-210802T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Benewah-Latah-Lewis-Nez Perce-Shoshone-
Including the cities of Winchester, Osburn, Nezperce, Kamiah,
Juliaetta, St Maries, Wallace, Tensed, Moscow, Deary, Kellogg,
Calder, Peck, Mullan, Smelterville, Craigmont, Lapwai, Kendrick,
Culdesac, Lewiston, Potlatch, Plummer, Gifford, Genesee, and
Pinehurst
348 PM PDT Sun Aug 1 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE TONIGHT...

The Flash Flood Watch continues for

* Portions of North and North Central Idaho, including the following 
  areas, in North Idaho, Benewah, Latah and Shoshone. In North 
  Central Idaho, Lewis and Nez Perce.

* Through late tonight.

* Thunderstorms with torrential rain combined with steep terrain 
  and/or previously fire burned areas could result in dangerous 
  flash flooding.

* Sudden rushes of water in creek and stream drainages could wash 
  away any person or thing nearby. Debris flows can cause additional 
  damage to low lying bridges or other structures. Road washouts are 
  common in flash flood events.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

vmt
645 
WGUS66 KOTX 020946
FFAOTX

Flood Watch
National Weather Service Spokane WA
246 AM PDT Mon Aug 2 2021

IDC009-057-061-069-079-021100-
/O.CAN.KOTX.FF.A.0003.000000T0000Z-210802T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Benewah-Latah-Lewis-Nez Perce-Shoshone-
Including the cities of Winchester, Osburn, Nezperce, Kamiah,
Juliaetta, St Maries, Wallace, Tensed, Moscow, Deary, Kellogg,
Calder, Peck, Mullan, Smelterville, Craigmont, Lapwai, Kendrick,
Culdesac, Lewiston, Potlatch, Plummer, Gifford, Genesee, and
Pinehurst
246 AM PDT Mon Aug 2 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for Portions of North and North Central Idaho, 
including the following areas, in North Idaho, Benewah, Latah and 
Shoshone. In North Central Idaho, Lewis and Nez Perce. has been 
cancelled.

The Flood Watch is cancelled. Flooding is no longer expected to pose 
a threat. Please continue to heed remaining road closures.

$$

AB

Nearby

Flash Flood Watches in Idaho, 2021Flash Flood Watches in Washington, 2021Every flash flood watch 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.