Alert archive / California / Flash Flood Warnings in 2011

Flash Flood Warning 2, NWS Los Angeles, CA

March 20, 2011Ventura County, California

NWS Los Angeles, CA issued this flash flood warning at Mar 20, 2011, 3:00 PM PDT for Ventura County, California. 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
Mar 20, 2011, 3:00 PM PDT (22:00 UTC)
Expired
Mar 20, 2011, 5:45 PM PDT
In force
3 hr
Issued by
NWS Los Angeles, CA
Area
Storm-based polygon
Flood severity
None

County Ventura County, CA

The radar

The Los Angeles radar (KVTX), 34 km from the middle of the area, began a volume at 22:02 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

Vandenberg AFB, CA (KVBG), launched 12:00Z, 10.0 hours before the alert went out and 153 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, Vandenberg AFB, CA at 12:00Z on 2011-03-20Temperature 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, Vandenberg AFB, CA at 12:00Z on 2011-03-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 78 square meters per square second.1939587897117Sfc1 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
500 m above ground
0-6 km bulk shear
72 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
297 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.

965 
WGUS56 KLOX 202200
FFWLOX
CAC111-210045-
/O.NEW.KLOX.FF.W.0002.110320T2200Z-110321T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE OXNARD CA
300 PM PDT SUN MAR 20 2011

THE NATIONAL WEATHER SERVICE IN OXNARD HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL VENTURA COUNTY IN SOUTHWEST CALIFORNIA...
  THIS INCLUDES THE CITIES OF CAMARILLO...OXNARD...SOMIS...AND POINT MUGU

* UNTIL 545 PM PDT

* AT 250 PM PDT...DOPPLER RADAR INDICATED A BAND OF VERY HEAVY RAIN
  FROM POINT MUGU...NORTHWARD THROUGH CAMARILLO INTO SANTA PAULA. THIS
  LINE OF INTENSE STORMS HAS BEEN NEARLY STATIONARY...PRODUCING RAINFALL
  RATES AS HIGH AS 1.2 INCHES PER HOUR. THIS LINE OF STORMS IS EXPECTED
  TO MOVE SLOWLY EASTWARD ACROSS THE COUNTY...LIKELY BRINGING DANGEROUS
  FLOODING OF ROADWAYS...STREAMS...AND CREEKS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO CAMARILLO...
  OXNARD...POINT MUGU...SOMIS....AND SANTA PAULA.
  
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 11880 3409 11893 3404 11896 3405 11896
      3406 11901 3409 11909 3409 11912 3411 11916
      3414 11920 3443 11917 3439 11884 3417 11875

$$

GOMBERG
2 follow-up statements
198 
WGUS76 KLOX 202333
FFSLOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
433 PM PDT SUN MAR 20 2011

CAC111-210045-
/O.CON.KLOX.FF.W.0002.000000T0000Z-110321T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
VENTURA CA-
433 PM PDT SUN MAR 20 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM PDT FOR SOUTH
CENTRAL VENTURA COUNTY...

AT 422 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A BAND OF VERY HEAVY RAIN EXTENDING FROM POINT MUGU NORTHWARD
THROUGH CAMARILLO. RAIN GAUGES INDICATED THAT RAINFALL RATES WERE STILL
UP NEAR 1 INCH PER HOUR ACROSS THE AREA...AND MORE THAN 2 INCHES OF RAIN
HAS FALLEN IN SOME AREAS IN TWO HOURS. THIS LINE OF SHOWERS WILL LINGER
ACROSS THE WARNING AREAS THROUGH 545 PM...LIKELY BRINGING DANGEROUS
FLOODING OF ROADWAYS...STREAMS...AND CREEKS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. MOVE
TO HIGHER GROUND. IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND
IMMEDIATELY. DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS
THE ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. 


LAT...LON 3417 11880 3409 11893 3404 11896 3405 11896
      3406 11901 3409 11909 3409 11912 3411 11916
      3414 11920 3443 11917 3439 11884 3417 11875

$$

BRUNO
731 
WGUS76 KLOX 210040
FFSLOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
540 PM PDT SUN MAR 20 2011

CAC111-210048-
/O.EXP.KLOX.FF.W.0002.000000T0000Z-110321T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
VENTURA CA-
540 PM PDT SUN MAR 20 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 545 PM PDT FOR SOUTH
CENTRAL VENTURA COUNTY...

THE LATEST RAIN GAGE DATA ACROSS VENTURA COUNTY INDICATED THAT 
RAINFALL RATES HAD DECREASED ACROSS THE WARNING AREA. THEREFORE THE 
FLASH FLOOD WARNING WILL BE ALLOWED TO EXPIRE AT 545 PM PDT.

ALTHOUGH THE FLASH FLOOD WARNING WILL BE ALLOWED TO EXPIRE...A FLOOD
ADVISORY REMAINS IN EFFECT FOR ALL OF VENTURA COUNTY UNTIL 730 PM 
PDT. 

LAT...LON 3417 11880 3409 11893 3404 11896 3405 11896
      3406 11901 3409 11909 3409 11912 3411 11916
      3414 11920 3443 11917 3439 11884 3417 11875

$$

RAT

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 19, 10:15 PM PDTAreal Flood AdvisoryLOXSan Luis Obispo6 hr
Mar 19, 10:26 PM PDTAreal Flood AdvisoryLOXSanta Barbara23 hr
Mar 20, 2:26 AM PDTSpecial Marine WarningLOX49 min
Mar 20, 4:03 AM PDTAreal Flood AdvisoryLOXSan Luis Obispo6 hr
Mar 20, 7:34 AM PDTAreal Flood AdvisoryLOXVentura12 hr
Mar 20, 8:39 AM PDTSmall Craft Advisory for Hazardous SeasLOX18 hr
Mar 20, 10:03 AM PDTAreal Flood AdvisoryLOXSan Luis Obispo, Santa Barbara117 min
Mar 20, 10:03 AM PDTFlash Flood WarningLOXSanta Barbara3 hr
Mar 20, 11:03 AM PDTAreal Flood AdvisoryLOXLos Angeles14 hr
Mar 20, 11:46 AM PDTRiver Flood WarningLOXSanta Barbara46 hr
Mar 20, 12:01 PM PDTAreal Flood AdvisoryLOXSan Luis Obispo, Santa Barbara3 hr
Mar 20, 2:59 PM PDTSevere Thunderstorm WarningLOXLos Angeles, Ventura61 min
Mar 20, 3:02 PM PDTRiver Flood WarningLOXVentura6 hr
Mar 20, 3:07 PM PDTAreal Flood AdvisoryLOXSan Luis Obispo, Santa Barbara3 hr
Mar 20, 3:25 PM PDTRiver Flood WarningLOXVentura18 hr

Nearby

Flash Flood Warnings in California, 2011Every flash flood warning in 2011

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.