Alert archive / California / Flash Flood Warnings in 2011

Flash Flood Warning 9, NWS Los Angeles, CA

July 5, 2011Los Angeles County, California

NWS Los Angeles, CA issued this flash flood warning at Jul 5, 2011, 5:14 PM PDT for Los Angeles County, California. It was in force for 2 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: Jul 5, 2011, 5:14 PM PDT (00:14 UTC)
Expired: Jul 5, 2011, 7:15 PM PDT
In force: 2 hr
Issued by: NWS Los Angeles, CA
Area: Storm-based polygon
Flood severity: None

County Los Angeles County, CA

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 0.2 hours before the alert went out and 212 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1564 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 32 m²/s²
0-3 km storm-relative helicity: 73 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.

283 
WGUS56 KLOX 060014
FFWLOX
CAC037-060215-
/O.NEW.KLOX.FF.W.0009.110706T0014Z-110706T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE OXNARD CA
514 PM PDT TUE JUL 5 2011

THE NATIONAL WEATHER SERVICE IN OXNARD HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN LOS ANGELES COUNTY IN SOUTHWEST CALIFORNIA...
  INCLUDING THE EASTERN ANTELOPE VALLEY AND ADJACENT FOOTHILLS

* UNTIL 715 PM PDT

* AT 506 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A CLUSTER OF STRONG THUNDERSTORMS IN THE EASTERN ANTELOPE VALLEY AND
  ADJACENT FOOTHILLS. THESE STORMS ARE PRODUCING VERY HEAVY RAINFALL
  AND WILL LIKELY CAUSE FLASH FLOODING OVER THE WARNED AREA. THE
  STORMS ARE DRIFTING SLOWLY WESTWARD TOWARDS PALMDALE.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO LAKE LOS
  ANGELES...LITTLE ROCK...PALMDALE...AND LANCASTER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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. MOVE TO HIGHER GROUND.

&&

LAT...LON 3435 11816 3483 11815 3483 11767 3482 11766
      3474 11766 3441 11765

$$

GOMBERG

3 follow-up statements

642 
WGUS76 KLOX 060027
FFSLOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
527 PM PDT TUE JUL 5 2011

CAC037-060215-
/O.CON.KLOX.FF.W.0009.000000T0000Z-110706T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LOS ANGELES CA-
527 PM PDT TUE JUL 5 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM PDT FOR
NORTHEASTERN LOS ANGELES COUNTY...INCLUDING THE EASTERN ANTELOPE VALLEY
AND ADJACENT FOOTHILLS.

AT 520 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A CLUSTER OF STRONG THUNDERSTORMS PRODUCING VERY HEAVY RAIN
OVER THE EASTERN ANTELOPE VALLEY AND ADJACENT FOOTHILLS. THE HEAVIEST
RAINFALL HAS OCCURRED ACROSS LAKE LOS ANGELES...WHERE AN AUTOMATED
RAIN GAUGE HAS REPORTED 1.01 INCHES BETWEEN 5 PM AND 520 PM. ALSO...A
TRAINED WEATHER SPOTTER HAS REPORTED STREET FLOODING OCCURRING IN LAKE
LOS ANGELES. ANOTHER AREA WHERE HEAVY RAINFALL IS OCCURRING INCLUDES
LITTLEROCK ALONG HIGHWAY 138. THESE STORMS ARE DRIFTING SLOWLY WESTWARD
AND WILL ALSO LIKELY IMPACT PORTIONS OF THE PALMDALE AND LANCASTER
METROPOLITAN AREAS. 

IN ADDITION TO HEAVY RAINFALL...THESE STORMS WILL BE CAPABLE OF PRODUCING
GUSTY WINDS...HAIL...AND DANGEROUS CLOUDS TO GROUND LIGHTNING. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO LAKE LOS
ANGELES...LITTLE ROCK...PALMDALE...AND LANCASTER

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 3435 11816 3483 11815 3483 11767 3482 11766
      3474 11766 3441 11765

$$

GOMBERG

869 
WGUS76 KLOX 060133
FFSLOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
633 PM PDT TUE JUL 5 2011

CAC037-060215-
/O.CON.KLOX.FF.W.0009.000000T0000Z-110706T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LOS ANGELES CA-
633 PM PDT TUE JUL 5 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM PDT FOR
NORTHEASTERN LOS ANGELES COUNTY...INCLUDING THE ANTELOPE VALLEY AND
ADJACENT FOOTHILLS.

AT 625 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF THUNDERSTORMS MOVING INTO PALMDALE AND LANCASTER
AND WILL BE IMPACTING HIGHWAY 14 SHORTLY. THESE STORMS WILL CONTINUE
TO PRODUCE BRIEF HEAVY RAINFALL...CAPABLE OF PRODUCING FLASH FLOODING
IN THE WARNING AREA. 

EARLIER...AN AUTOMATED RAIN GAUGE IN LAKE LOS ANGELES REPORTED 1.11 INCHES
OF RAIN BETWEEN 5 PM AND 6 PM...MOST OF WHICH FELL IN A 20 MINUTE TIME
PERIOD. ALSO...A TRAINED WEATHER SPOTTER AND CALIFORNIA HIGHWAY PATROL
REPORTED STREET FLOODING IN LAKE LOS ANGELES.

IN ADDITION TO HEAVY RAINFALL...THESE STORMS WILL BE CAPABLE OF PRODUCING
GUSTY WINDS...SMALL HAIL...AND DANGEROUS CLOUDS TO GROUND LIGHTNING. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...
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. MOVE TO HIGHER GROUND.

&&

LAT...LON 3435 11816 3483 11815 3483 11767 3482 11766
      3474 11766 3441 11765

$$

GOMBERG

027 
WGUS76 KLOX 060217
FFSLOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
717 PM PDT TUE JUL 5 2011

CAC037-060226-
/O.EXP.KLOX.FF.W.0009.000000T0000Z-110706T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LOS ANGELES CA-
717 PM PDT TUE JUL 5 2011

...THE FLASH FLOOD WARNING HAS EXPIRED FOR NORTHEASTERN LOS ANGELES
COUNTY...

THE CLUSTER OF THUNDERSTORMS THAT AFFECTED THE ANTELOPE VALLEY HAS
DIMINISHED IN AREAL COVERAGE AND INTENSITY...ALLOWING FOR THE EXPIRATION
OF THE FLASH FLOOD WARNING. HOWEVER...ADDITIONAL STORMS ARE STILL POSSIBLE
THIS EVENING...WITH THE POTENTIAL FOR ADDITIONAL HEAVY RAINFALL.

LAT...LON 3435 11816 3483 11815 3483 11767 3482 11766
      3474 11766 3441 11765

$$

GOMBERG

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 5, 7:33 PM PDT	Special Weather Statement	LOX	Ventura	57 min
Jul 6, 3:31 AM PDT	Flash Flood Watch	LOX	Santa Barbara	17 hr
Jul 6, 12:05 PM PDT	Flash Flood Warning	LOX	Los Angeles	3 hr
Jul 6, 1:28 PM PDT	Flash Flood Warning	LOX	Ventura	3 hr
Jul 6, 1:55 PM PDT	Flash Flood Warning	LOX	Los Angeles	3 hr
Jul 6, 4:56 PM PDT	Special Weather Statement	LOX		49 min

Nearby

Flash Flood Warnings in California, 2011 Every 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.