Alert archive / California / Flash Flood Warnings in 2011

Flash Flood Warning 21, NWS Los Angeles, CA

September 13, 2011San Luis Obispo County, Santa Barbara County, California

NWS Los Angeles, CA issued this flash flood warning at Sep 13, 2011, 4:40 PM PDT for San Luis Obispo County, Santa Barbara 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
Sep 13, 2011, 4:40 PM PDT (23:40 UTC)
Expired
Sep 13, 2011, 7:30 PM PDT
In force
3 hr
Issued by
NWS Los Angeles, CA
Area
Storm-based polygon
Flood severity
None

Counties San Luis Obispo County, CA, Santa Barbara County, CA

The nearest sounding before it

Vandenberg AFB, CA (KVBG), launched 12:00Z, 11.7 hours before the alert went out and 78 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 2011-09-13Temperature 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 2011-09-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 square meters per square second.1939Sfc1 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
1388 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
16 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.

149 
WGUS56 KLOX 132340
FFWLOX
CAC079-083-140230-
/O.NEW.KLOX.FF.W.0021.110913T2340Z-110914T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE OXNARD CA
440 PM PDT TUE SEP 13 2011

THE NATIONAL WEATHER SERVICE IN OXNARD HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN SAN LUIS OBISPO COUNTY IN SOUTHWEST CALIFORNIA...
  NORTH CENTRAL SANTA BARBARA COUNTY IN SOUTHWEST CALIFORNIA...

* UNTIL 730 PM PDT

* AT 430 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA. RADAR     
  RAINFALL RATES WITH THIS STORM EXCEED 2 INCHES PER HOUR.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO            
  CALIFORNIA VALLEY...CUYAMA VALLEY AND HIGHWAY 166. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A FEW INCHES OF
RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE.

&&

LAT...LON 3535 11980 3527 11980 3526 11967 3476 11959
      3478 12004 3539 12011

$$

DANIELSON
2 follow-up statements
730 
WGUS76 KLOX 140106
FFSLOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
606 PM PDT TUE SEP 13 2011

CAC079-083-140230-
/O.CON.KLOX.FF.W.0021.000000T0000Z-110914T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SANTA BARBARA CA-SAN LUIS OBISPO CA-
606 PM PDT TUE SEP 13 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM PDT FOR
SOUTHEASTERN SAN LUIS OBISPO AND NORTH CENTRAL SANTA BARBARA
COUNTIES...

AT 550 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED THAT 
THUNDERSTORMS OVER THE REGION HAVE DIMINISHED GREATLY. HOWEVER... 
SHOWERS AND THUNDERSTORMS CONTINUE OVER THE SANTA BARBARA COUNTY 
PORTIONS OF THE WARNED AREA. DUE TO THE THREAT OF FLOODING FROM 
THESE STORMS AND THOSE THAT OCCURRED EARLIER...THE FLASH FLOOD 
WARNING REMAINS IN EFFECT OVER THE WARNED AREA UNTIL 730 PM.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO CALIFORNIA 
VALLEY AND CUYAMA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IT IS IMPORTANT TO KNOW WHERE YOU ARE RELATIVE TO STREAMS... 
RIVERS...OR CREEKS WHICH CAN BECOME KILLERS IN HEAVY RAINS. CAMPERS 
AND HIKERS SHOULD AVOID STREAMS OR CREEKS.

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

&&

LAT...LON 3535 11980 3527 11980 3526 11967 3476 11959
      3478 12004 3539 12011

$$

DANIELSON
037 
WGUS76 KLOX 140225
FFSLOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE OXNARD CA
725 PM PDT TUE SEP 13 2011

CAC079-083-140232-
/O.EXP.KLOX.FF.W.0021.000000T0000Z-110914T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SANTA BARBARA CA-SAN LUIS OBISPO CA-
725 PM PDT TUE SEP 13 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 730 PM PDT FOR SOUTHEASTERN
SAN LUIS OBISPO AND NORTH CENTRAL SANTA BARBARA COUNTIES...

THUNDERSTORM ACTIVITY HAS DIMINISHED OVER THE SANTA BARBARA AND SAN 
LUIS OBISPO COUNTY MOUNTAINS AND INTERIOR VALLEYS. THERE COULD BE A 
FEW MORE STORM CELLS MOVE THROUGH THE EASTERN PORTION OF THESE 
COUNTIES. BUT ANY THUNDERSTORMS THAT DO DEVELOP SHOULD BE MUCH 
WEAKER IN INTENSITY. 

LAT...LON 3535 11980 3527 11980 3526 11967 3476 11959
      3478 12004 3539 12011

$$

KAPLAN

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 13, 1:18 PM PDTAreal Flood AdvisoryLOXLos Angeles2 hr
Sep 13, 2:47 PM PDTSpecial Weather StatementLOXLos Angeles58 min
Sep 13, 3:11 PM PDTSevere Thunderstorm WarningLOXLos Angeles, Ventura64 min
Sep 13, 3:34 PM PDTFlash Flood WarningLOXLos Angeles3 hr
Sep 13, 4:08 PM PDTFlash Flood WarningLOXSanta Barbara, Ventura3 hr
Sep 13, 4:50 PM PDTSpecial Weather StatementLOXSan Luis Obispo55 min

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.