Alert archive / California / Flash Flood Warnings in 2006

Flash Flood Warning 21, NWS Los Angeles, CA

December 9, 2006Los Angeles County, Ventura County, California

NWS Los Angeles, CA issued this flash flood warning at Dec 9, 2006, 11:57 PM PST for Los Angeles County, Ventura County, California. It was in force for 63 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Dec 9, 2006, 11:57 PM PST (07:57 UTC)
Expired
Dec 10, 2006, 1:00 AM PST
In force
63 min
Issued by
NWS Los Angeles, CA
Area
Counties, with a storm outline in the text

Counties Los Angeles County, CA, Ventura County, CA

The radar

The Los Angeles radar (KVTX), 47 km from the middle of the area, began a volume at 07:59 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

Edwards AFB, CA (KEDW), launched 00:00Z, 8.0 hours before the alert went out and 114 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, Edwards AFB, CA at 00:00Z on 2006-12-10Temperature 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, Edwards AFB, CA at 00:00Z on 2006-12-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -23 square meters per square second.1939587897117136Sfc1 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
1956 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
-23 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, in the capitals the NWS used until 2016.

000 
WGUS56 KLOX 100759
FFWLOX
CAC037-111-100900-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE OXNARD CA
1157 PM PST SAT DEC 9 2006

THE NATIONAL WEATHER SERVICE IN OXNARD HAS ISSUED A

* FLASH FLOOD WARNING FOR...THE TOPANGA BURN AREA IN
  WEST CENTRAL LOS ANGELES COUNTY IN SOUTHWEST CALIFORNIA
  SOUTHEASTERN VENTURA COUNTY IN SOUTHWEST CALIFORNIA

* UNTIL 100 AM PST

* AT 1147 PM PST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED  
  HEAVY RAINFALL INTENSITIES APPROACHING THE TOPANGA BURN AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SIMI       
  VALLEY AND CHATSWORTH.

RESIDENTS AND MOTORISTS IN AND BELOW RECENTLY BURNED AREAS SHOULD BE
ALERT TO HEAVY MUD AND DEBRIS FLOWS WHICH MAY BLOCK ROADS AND
CULVERTS. POTENTIALLY DANGEROUS FLOODING AND PROPERTY LOSS COULD
RESULT IN AREAS WHERE RUNOFF IS RESTRICTED OR BLOCKED.

IN ADDITION TO FLASH FLOODING...RAINFALL IS EXPECTED TO CAUSE DEBRIS
FLOWS IN THE TOPANGA BURN AREA...ACCORDING TO THRESHOLDS PROVIDED BY
THE USGS. AREAS AFFECTED INCLUDE HIGHWAY 118 NEAR SANTA SUSANA
PASS...SANTA SUSANA PASS ROAD...AND RESIDENCES IN AND BELOW THE BURN
AREA.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

LAT...LON 3417 11883 3415 11863 3430 11860 3427 11876

$$

KAPLAN/HALL
2 follow-up statements
000 
WGUS76 KLOX 100831
FFSLOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
1227 AM PST SUN DEC 10 2006

CAC037-111-100900-
LOS ANGELES-VENTURA-
1227 AM PST SUN DEC 10 2006

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 100 AM PST FOR THE 
TOPANGA BURN AREA IN SOUTHEASTERN VENTURA AND WEST CENTRAL LOS 
ANGELES COUNTIES...

AT 1222 AM PST...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE MODERATE TO LOCALLY HEAVY RAIN OVER THE TOPANGA BURN AREA. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SIMI VALLEY 
AND CHATSWORTH.

RESIDENTS AND MOTORISTS IN AND BELOW RECENTLY BURNED AREAS SHOULD BE 
ALERT TO HEAVY MUD AND DEBRIS FLOWS WHICH MAY BLOCK ROADS AND 
CULVERTS. POTENTIALLY DANGEROUS FLOODING AND PROPERTY LOSS COULD 
RESULT IN AREAS WHERE RUNOFF IS RESTRICTED OR BLOCKED.

IN ADDITION TO FLASH FLOODING...RAINFALL IS EXPECTED TO CAUSE DEBRIS
FLOWS IN THE TOPANGA BURN AREA...ACCORDING TO THRESHOLDS PROVIDED BY
THE USGS. AREAS AFFECTED INCLUDE HIGHWAY 118 NEAR SANTA SUSANA
PASS...SANTA SUSANA PASS ROAD...AND RESIDENCES IN AND BELOW THE BURN
AREA.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY 
AUTOMOBILE.

LAT...LON 3417 11883 3415 11863 3430 11860 3427 11876

$$

KAPLAN
000 
WGUS76 KLOX 100908
FFSLOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
106 AM PST SUN DEC 10 2006

CAC037-111-100916-
LOS ANGELES-VENTURA-
106 AM PST SUN DEC 10 2006

...THE FLASH FLOOD WARNING HAS EXPIRED FOR SOUTHEASTERN VENTURA AND
WEST CENTRAL LOS ANGELES COUNTIES...

SHOWERS HAVE QUICKLY EXITED THE TOPANGA BURN AREA WITH ONLY A FEW 
SHOWERS EXPECTED TO MOVE ACROSS THE AREA OVERNIGHT.

LAT...LON 3417 11883 3415 11863 3430 11860 3427 11876

$$

KAPLAN

The office that day

Everything else NWS Los Angeles, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 9, 6:29 PM PSTSpecial Marine WarningLOX61 min
Dec 9, 8:40 PM PSTFlash Flood WarningLOXLos Angeles, Ventura65 min
Dec 9, 9:21 PM PSTFlash Flood WarningLOXLos Angeles, Ventura54 min

Nearby

Flash Flood Warnings in California, 2006Every flash flood warning in 2006

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.