Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 5, NWS Los Angeles, CA

October 11, 2012Ventura County, California

NWS Los Angeles, CA issued this flash flood warning at Oct 11, 2012, 1:02 PM PDT for Ventura County, California. It was in force for 3 hr. 2 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: Oct 11, 2012, 1:02 PM PDT (20:02 UTC)
Expired: Oct 11, 2012, 4:00 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), 42 km from the middle of the area, began a volume at 20:05 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.

What was reported inside it

Time	Report	Where	Remark
Oct 11, 1:07 PM PDT	HEAVY RAIN 1	3 Ne Simi Valley, CA	TRAINED SPOTTER REPORT 1.0 INCH OF RAIN IN 15 MINUTES.
Oct 11, 1:33 PM PDT	HEAVY RAIN 1.5	3 Ne Simi Valley, CA	TRAINED SPOTTER REPORTED 1.5 INCHES OF RAIN IN 30 MINUTES. WATER RISING TO 2 INCHES ABOVE CURB LEVEL.

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

The nearest sounding before it

Vandenberg AFB, CA (KVBG), launched 12:00Z, 8.0 hours before the alert went out and 168 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: 14 J/kg
Mixed-layer CIN: -186 J/kg
Mixed-layer LCL: 952 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: 1 m²/s²
0-3 km storm-relative helicity: -28 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.

759 
WGUS56 KLOX 112002
FFWLOX
CAC111-112300-
/O.NEW.KLOX.FF.W.0005.121011T2002Z-121011T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE OXNARD CA
102 PM PDT THU OCT 11 2012

THE NATIONAL WEATHER SERVICE IN OXNARD HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN VENTURA COUNTY IN SOUTHWEST CALIFORNIA...

* UNTIL 400 PM PDT

* AT 1257 PM PDT...NATIONAL WEATHER SERVICE TRAINED WEATHER SPOTTERS 
  REPORTED RAINFALL OVER ONE INCH OCCURRING IN FIFTEEN MINUTES. FLASH 
  FLOODING FROM THIS THUNDERSTORM WILL OCCUR OVER THE WARNED AREA.

* THE STORM WILL PRODUCE FLASH FLOODING IN THE SIMI VALLEY AREA 
  IMPACTING ARROYO SIMI AND ASSOCIATED DRAINAGES IN THE AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

&&

LAT...LON 3428 11888 3439 11879 3439 11869 3425 11864
      3424 11867 3419 11867 3420 11876

$$

HALL

3 follow-up statements

473 
WGUS76 KLOX 112042
FFSLOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
142 PM PDT THU OCT 11 2012

CAC111-112300-
/O.CON.KLOX.FF.W.0005.000000T0000Z-121011T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
VENTURA CA-
142 PM PDT THU OCT 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 400 PM PDT FOR
SOUTHEASTERN VENTURA COUNTY...

AT 135 PM PDT...NATIONAL WEATHER SERVICE TRAINED WEATHER SPOTTERS IN 
SIMI VALLEY HAVE REPORTED RAINFALL RATES IN EXCESS OF ONE-INCH PER 
HOUR HAVE OCCURRED ACROSS THE EASTERN PORTION OF THE VALLEY. WATER 
IS FLOWING IN AREA DRAINAGES...AND ON AREA STREETS...RUNOFF IS 
TOPPING THE CURB-LEVEL. A FLASH FLOOD WARNING REMAINS IN EFFECT. IF 
ENCOUNTERING A FLOODED ROADWAY...TURN AROUND...DONT DROWN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

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 3428 11888 3439 11879 3439 11869 3425 11864
      3424 11867 3419 11867 3420 11876

$$

HALL

073 
WGUS76 KLOX 112156
FFSLOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
256 PM PDT THU OCT 11 2012

CAC111-112300-
/O.CON.KLOX.FF.W.0005.000000T0000Z-121011T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
VENTURA CA-
256 PM PDT THU OCT 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 400 PM PDT FOR
SOUTHEASTERN VENTURA COUNTY...

AT 251 PM PDT...NATIONAL WEATHER SERVICE TRAINED WEATHER SPOTTERS 
HAVE REPORTED FLOODING OCCURRING ACROSS EASTERN SIMI VALLEY. 
ALTHOUGH SHOWERS HAVE TAPERED OFF THIS AFTERNOON...WASHES ARE STILL 
FLOWING AND A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 400 PM 
PDT. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFUL
ENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODED
ROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN
OXNARD.

&&

LAT...LON 3428 11888 3439 11879 3439 11869 3425 11864
      3424 11867 3419 11867 3420 11876

$$

HALL

592 
WGUS76 KLOX 112301
FFSLOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
401 PM PDT THU OCT 11 2012

CAC111-112307-
/O.EXP.KLOX.FF.W.0005.000000T0000Z-121011T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
VENTURA CA-
401 PM PDT THU OCT 11 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 400 PM PDT FOR SOUTHEASTERN
VENTURA COUNTY...

THUNDERSTORMS HAVE DIMINISHED OVER THE WARNED AREA...THEREFORE THE 
FLASH FLOOD WARNING HAS BEEN ALLOWED TO EXPIRE. THERE WILL CONTINUE 
TO BE POP UP THUNDERSTORMS ACROSS PORTIONS OF VENTURA AND LOS 
ANGELES COUNTIES THIS AFTERNOON AND EVENING. AN URBAN AND SMALL 
STREAM FLOOD ADVISORY REMAINS IN EFFECT FOR PORTIONS OF VENTURA AND 
LOS ANGELES COUNTIES UNTIL 530 PM PDT THIS AFTERNOON. 

LAT...LON 3428 11888 3439 11879 3439 11869 3425 11864
      3424 11867 3419 11867 3420 11876

$$

KAPLAN/GOMBERG

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 11, 4:02 AM PDT	Special Marine Warning	LOX		28 min
Oct 11, 4:09 AM PDT	Special Weather Statement	LOX	Los Angeles	51 min
Oct 11, 5:41 AM PDT	Special Marine Warning	LOX		49 min
Oct 11, 6:26 AM PDT	Special Marine Warning	LOX		34 min
Oct 11, 6:31 AM PDT	Special Weather Statement	LOX	Los Angeles	44 min
Oct 11, 6:32 AM PDT	Special Weather Statement	LOX	Los Angeles	43 min
Oct 11, 8:32 AM PDT	Special Marine Warning	LOX		58 min
Oct 11, 8:50 AM PDT	Special Marine Warning	LOX		55 min
Oct 11, 10:00 AM PDT	Special Marine Warning	LOX		60 min
Oct 11, 12:39 PM PDT	Areal Flood Advisory	LOX	Los Angeles	111 min
Oct 11, 12:54 PM PDT	Areal Flood Advisory	LOX		111 min
Oct 11, 1:35 PM PDT	Areal Flood Advisory	LOX	Los Angeles	115 min
Oct 11, 1:51 PM PDT	Areal Flood Advisory	LOX	Santa Barbara	114 min
Oct 11, 2:47 PM PDT	Special Weather Statement	LOX	Los Angeles	28 min
Oct 11, 2:55 PM PDT	Flash Flood Warning	LOX	Los Angeles	98 min
Oct 11, 3:29 PM PDT	Special Weather Statement	LOX	Los Angeles	31 min
Oct 11, 3:35 PM PDT	Areal Flood Advisory	LOX	Los Angeles	115 min
Oct 11, 4:37 PM PDT	Flash Flood Warning	LOX	Los Angeles	113 min
Oct 11, 4:46 PM PDT	Special Marine Warning	LOX		29 min
Oct 11, 4:54 PM PDT	Special Weather Statement	LOX	Orange	51 min

Nearby

Flash Flood Warnings in California, 2012 Every flash flood warning in 2012

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.