Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 17, NWS San Diego, CA

August 13, 2012Riverside County, San Diego County, California

NWS San Diego, CA issued this flash flood warning at Aug 13, 2012, 1:31 PM PDT for Riverside County, San Diego 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
Aug 13, 2012, 1:31 PM PDT (20:31 UTC)
Expired
Aug 13, 2012, 3:54 PM PDT
In force
2 hr
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

Counties Riverside County, CA, San Diego County, CA

The radar

The San Diego radar (KNKX), 78 km from the middle of the area, began a volume at 20:33 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

San Diego, CA (KNKX), launched 12:00Z, 8.5 hours before the alert went out and 97 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, San Diego, CA at 12:00Z on 2012-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 446 joules per kilogram.LCLLFCEL10008507005003002001001 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, San Diego, CA at 12:00Z on 2012-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 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
446 J/kg
Mixed-layer CIN
-661 J/kg
Mixed-layer LCL
1527 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
67 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.

409 
WGUS56 KSGX 132031
FFWSGX
CAC065-073-132330-
/O.NEW.KSGX.FF.W.0017.120813T2031Z-120813T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
131 PM PDT MON AUG 13 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL RIVERSIDE COUNTY IN SOUTHERN CALIFORNIA...
  NORTH CENTRAL SAN DIEGO COUNTY IN SOUTHWEST CALIFORNIA...

* UNTIL 430 PM PDT

* AT 124 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  FLASH FLOODING FROM A LINE OF THUNDERSTORMS AND HEAVY SHOWERS OVER 
  THE SAN DIEGO AND WESTERN RIVERSIDE COUNTY MOUNTAINS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO            
  ANZA...LAKE HEMET...AND WARNER SPRINGS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

LAT...LON 3389 11691 3388 11657 3310 11642 3306 11672

$$

HARRISON
2 follow-up statements
628 
WGUS76 KSGX 132204
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
304 PM PDT MON AUG 13 2012

CAC073-132211-
/O.CAN.KSGX.FF.W.0017.000000T0000Z-120813T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-
304 PM PDT MON AUG 13 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTH CENTRAL SAN
DIEGO COUNTY...

THUNDERSTORMS AND HEAVY SHOWERS HAVE DISSIPATED OVER THE AREA...AND 
SO THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR THE NORTHERN SAN 
DIEGO COUNTY MOUNTAINS.

LAT...LON 3361 11652 3359 11684 3389 11691 3388 11657

$$

CAC065-132330-
/O.CON.KSGX.FF.W.0017.000000T0000Z-120813T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
304 PM PDT MON AUG 13 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM PDT FOR
CENTRAL RIVERSIDE COUNTY...

AT 254 PM PDT...ALTHOUGH THUNDERSTORMS AND HEAVY SHOWERS HAVE 
WEAKENED OVER PORTIONS OF THE WESTERN RIVERSIDE COUNTY 
MOUNTAINS...MORE STORMS MAY DEVELOP...AND RUN-OFF FROM PREVIOUS 
RAINFALL MAY CONTINUE. THUS...THE FLASH FLOOD WARNING CONTINUES.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SAN JACINTO
PEAK...LAKE HEMET...IDYLLWILD-PINE COVE AND IDYLLWILD

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

LAT...LON 3361 11652 3359 11684 3389 11691 3388 11657

$$

HARRISON
580 
WGUS76 KSGX 132254
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
354 PM PDT MON AUG 13 2012

CAC065-132304-
/O.CAN.KSGX.FF.W.0017.000000T0000Z-120813T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
354 PM PDT MON AUG 13 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CENTRAL RIVERSIDE
COUNTY...

HEAVY SHOWERS AND THUNDERSTORMS HAVE DISSIPATED OVER THE RIVERSIDE 
COUNTY MOUNTAINS SOUTH OF BANNING PASS. THUS...THE FLASH FLOOD 
WARNING HAS BEEN CANCELLED.

LAT...LON 3361 11652 3359 11684 3389 11691 3388 11657

$$

HARRISON

The office that day

Everything else NWS San Diego, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 12, 5:29 PM PDTSevere Thunderstorm WarningSGXSan Diego46 min
Aug 12, 5:53 PM PDTFlash Flood WarningSGXSan Diego3 hr
Aug 12, 6:14 PM PDTSevere Thunderstorm WarningSGXSan Diego46 min
Aug 12, 7:23 PM PDTAreal Flood AdvisorySGXRiverside, San Diego112 min
Aug 13, 3:23 AM PDTFlash Flood WatchSGXRiverside, San Bernardino, San Diego16 hr
Aug 13, 11:43 AM PDTSpecial Weather StatementSGX47 min
Aug 13, 11:54 AM PDTAreal Flood AdvisorySGXSan Bernardino65 min
Aug 13, 12:19 PM PDTFlash Flood WarningSGXSan Diego2 hr
Aug 13, 12:28 PM PDTSpecial Weather StatementSGXSan Diego62 min
Aug 13, 12:35 PM PDTFlash Flood WarningSGXSan Diego2 hr
Aug 13, 12:58 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino3 hr
Aug 13, 1:22 PM PDTSpecial Weather StatementSGXSan Diego53 min
Aug 13, 1:37 PM PDTFlash Flood WarningSGXSan Bernardino3 hr
Aug 13, 3:06 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino97 min

Nearby

Flash Flood Warnings in California, 2012Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.