Alert archive / Washington / Flash Flood Warnings in 2014

Flash Flood Warning 21, NWS Spokane, WA

August 21, 2014Okanogan County, Washington

NWS Spokane, WA issued this flash flood warning at Aug 21, 2014, 7:15 PM PDT for Okanogan County, Washington. It was in force for 3 hr. 6 reports 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: Aug 21, 2014, 7:15 PM PDT (02:15 UTC)
Expired: Aug 21, 2014, 10:15 PM PDT
In force: 3 hr
Issued by: NWS Spokane, WA
Area: Storm-based polygon
Flood severity: None

County Okanogan County, WA

The radar

The Spokane radar (KOTX), 184 km from the middle of the area, began a volume at 02:16 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
Aug 21, 7:32 PM PDT	HEAVY RAIN 1.15	4 Se Twisp, WA	SPOTTER OKANOGAN 82 4 SE TWISP ON BEAVER CREEK ROAD REPORTED 1.15 IN RAIN OVER LAST HOUR FROM THUNDERSTORMS.
Aug 21, 7:45 PM PDT	FLASH FLOOD	10 E Twisp, WA	HIGHWAY 20 NEAR FRAZER CREEK CLOSED DUE TO MULTIPLE DEBRIS FLOWS ACROSS HIGHWAY.
Aug 21, 7:45 PM PDT	FLASH FLOOD	10 E Twisp, WA	HIGHWAY 20 NEAR FRAZER CREEK CLOSED DUE TO MULTIPLE DEBRIS FLOWS ACROSS HIGHWAY. HIGHWAY 20 CLOSED FROM B-O ROAD TO HIGHWAY 153/20 INTERSECTION MILEPOSTS 204 TO 229. WASHINGTON DOT REPORTS ROAD IS PARTIALLY WASHED AWAY IN PLACES AND UNSAFE FOR TRAVEL.
Aug 21, 7:45 PM PDT	FLASH FLOOD	8 E Twisp, WA	REPORTS OF VEHICLES TRAPPED IN WATER ON BENSON CREEK ROAD.
Aug 21, 10:00 PM PDT	FLASH FLOOD	6 Sw Okanogan, WA	CHILIWIST AREA UNDER MANDATORY EVACUATIONS IF POSSIBLE DUE TO SEVERE FLOODING FROM STORMS. SHERIFF ISSUED SHELTER IN PLACE IF YOU CANNOT SAFELY LEAVE THE AREA. ROAD CONDITIONS DETERIORATING FAST.
Aug 21, 10:00 PM PDT	FLASH FLOOD	6 Sw Okanogan, WA	CHILIWIST AREA UNDER MANDATORY EVACUATIONS IF POSSIBLE DUE TO SEVERE FLOODING FROM STORMS. SHERIFF ISSUED SHELTER IN PLACE IF YOU CANNOT SAFELY LEAVE THE AREA. ROAD CONDITIONS DETERIORATING FAST. AREA CUT-OFF DUE TO DAMAGED ROADWAYS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Spokane, WA (KOTX), launched 00:00Z, 2.3 hours before the alert went out and 272 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: 402 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 1944 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 21 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, in the capitals the NWS used until 2016.

180 
WGUS56 KOTX 220215
FFWOTX
WAC047-220515-
/O.NEW.KOTX.FF.W.0021.140822T0215Z-140822T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SPOKANE WA
715 PM PDT THU AUG 21 2014

THE NATIONAL WEATHER SERVICE IN SPOKANE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN OKANOGAN COUNTY IN NORTHEAST WASHINGTON...

* UNTIL 1015 PM PDT
    
* AT 712 PM PDT...EMERGENCY MANAGEMENT REPORTED FLASH FLOODING NEAR 
  BENSON CREEK...OR ABOUT 6 MILES SOUTHEAST OF TWISP AS HEAVY 
  RAINFALL FROM SLOW MOVING THUNDERSTORMS CONTINUE IN THE AREA.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  OMAK...OKANOGAN...BREWSTER...TWISP...PATEROS...WINTHROP...FOGGY DEW
  CAMPGROUND...CRATER CREEK CAMPGROUND...LOUP LOUP CAMPGROUND...
  MONSE...LOUP LOUP PASS...METHOW...BLACK PINE LAKE CAMPGROUND...
  MALOTT...CARLTON...MAZAMA...MYSTERY CAMPGROUND AND WAR CREEK
  CAMPGROUND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

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.

THE AFFECTED AREAS ARE THE COUGAR COMPLEX FIRE BURN SCARS BETWEEN 
THE OKANOGAN AND METHOW RIVERS...CARLTON COMPLEX...LONE MOUNTAIN 
FIRE BURN SCAR...ALONG WITH OTHER BURN SCARS IN THE AREA. HIGH 
INTENSITY RAINFALL ON THE BURNED AREAS MAY CAUSE DANGEROUS FLASH 
FLOODING AND DEBRIS FLOWS. RESIDENTS AND MOTORISTS IN AND BELOW THE 
COUGAR COMPLEX FIRE BURN SCAR IN THE METHOW AND OKANOGAN 
VALLEYS...INCLUDING MOTORISTS ON STATE HIGHWAY 20 BETWEEN TWISP AND 
THE OKANOGAN RIVER...US HIGHWAY 97 NORTH FROM BREWSTER TO 
MALOTT...AND STATE HIGHWAY 153 FROM CARLTON TO WINTHROP...SHOULD 
TAKE IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND PROPERTY.


&&

LAT...LON 4844 11948 4801 11967 4809 11967 4808 11972
      4810 11977 4806 11989 4796 11988 4796 11998
      4804 12015 4807 12015 4812 12031 4816 12036
      4822 12035 4831 12054 4862 12042

$$

RP

2 follow-up statements

800 
WGUS76 KOTX 220421
FFSOTX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SPOKANE WA
921 PM PDT THU AUG 21 2014

WAC047-220515-
/O.CON.KOTX.FF.W.0021.000000T0000Z-140822T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
OKANOGAN WA-
921 PM PDT THU AUG 21 2014

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 PM PDT FOR
SOUTHWESTERN OKANOGAN COUNTY...

AT 914 PM PDT...EMERGENCY MANAGEMENT AND THE PUBLIC RELAYED REPORTS 
OF NUMEROUS DEBRIS FLOWS CAUSING PROBLEMS ON ROADWAYS IN THE 
AREA...SUCH AS ON HIGHWAY 20 NEAR FRAZER CREEK WHICH HAS BEEN CLOSED 
DUE TO MULTIPLE DEBRIS FLOWS. REPORTS OF FLASH FLOODING PUSHING A 
CAR AGAINST A TREE NEAR BENSON CREEK HAVE ALSO BEEN RELAYED. 
WEAKENING SLOW MOVING THUNDERSTORMS REMAIN IN THE AREA AND CONTINUE 
TO PRODUCE RAINFALL SO THE FLASH FLOOD WARNING REMAINS IN EFFECT. 
DEBRIS FLOW CAN CONSIST OF ROCK...MUD...VEGETATION AND OTHER LOOSE 
MATERIALS.

SOME LOCATIONS THAT WILL EXPERIENCE FLOODING OR DEBRIS FLOWS 
INCLUDE... OMAK...OKANOGAN...BREWSTER...TWISP...PATEROS...WINTHROP 
...FOGGY DEW CAMPGROUND...CRATER CREEK CAMPGROUND...LOUP LOUP 
CAMPGROUND... MONSE...LOUP LOUP PASS...METHOW...BLACK PINE LAKE 
CAMPGROUND... MALOTT...CARLTON...MAZAMA...MYSTERY CAMPGROUND AND WAR 
CREEK CAMPGROUND.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

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 4844 11948 4801 11967 4809 11967 4808 11972
      4810 11977 4806 11989 4796 11988 4796 11998
      4804 12015 4807 12015 4812 12031 4816 12036
      4822 12035 4831 12054 4862 12042

$$

RP

075 
WGUS76 KOTX 220513
FFSOTX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SPOKANE WA
1013 PM PDT THU AUG 21 2014

WAC047-220521-
/O.EXP.KOTX.FF.W.0021.000000T0000Z-140822T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
OKANOGAN WA-
1013 PM PDT THU AUG 21 2014

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN OKANOGAN COUNTY WILL
EXPIRE AT 1015 PM PDT...

THE HEAVY RAIN HAS ENDED...THEREFORE THE FLASH FLOOD WARNING HAS 
BEEN ALLOWED TO EXPIRE...HOWEVER A FLASH FLOOD WATCH REMAINS IN 
EFFECT THROUGH FRIDAY EVENING. 

LAT...LON 4844 11948 4801 11967 4809 11967 4808 11972
      4810 11977 4806 11989 4796 11988 4796 11998
      4804 12015 4807 12015 4812 12031 4816 12036
      4822 12035 4831 12054 4862 12042

$$

RP

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 6:00 PM PDT	Areal Flood Advisory	OTX	Okanogan	3 hr
Aug 21, 6:11 PM PDT	Special Weather Statement	OTX	Douglas	64 min
Aug 21, 6:16 PM PDT	Severe Thunderstorm Warning	OTX	Chelan, Douglas	19 min
Aug 21, 6:37 PM PDT	Areal Flood Advisory	OTX	Stevens	113 min
Aug 21, 6:51 PM PDT	Special Weather Statement	OTX	Douglas	24 min
Aug 22, 8:10 AM PDT	Areal Flood Advisory	OTX	Spokane, Stevens	50 min
Aug 22, 4:51 PM PDT	Areal Flood Advisory	OTX	Ferry	3 hr

Nearby

Flash Flood Warnings in Washington, 2014 Every flash flood warning in 2014

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.