Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 40, NWS San Diego, CA

September 9, 2012San Diego County, California

NWS San Diego, CA issued this flash flood warning at Sep 9, 2012, 5:30 PM PDT for San Diego County, California. It was in force for 104 min. 3 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
Sep 9, 2012, 5:30 PM PDT (00:30 UTC)
Expired
Sep 9, 2012, 7:14 PM PDT
In force
104 min
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

County San Diego County, CA

The radar

The San Diego radar (KNKX), 42 km from the middle of the area, began a volume at 00:32 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

TimeReportWhereRemark
Sep 9, 5:39 PM PDTHEAVY RAIN 1.124 Ese Pauma Valley, CARED GATE REPEATER MEASURED 1.12 INCHES OF RAIN BETWEEN 1628-1739 PDT.
Sep 9, 5:52 PM PDTHEAVY RAIN 0.752 Se Pauma Valley, CARINCON SPRINGS MEASURED 0.75 INCHES OF RAIN BETWEEN 1635-1752 PDT.
Sep 9, 6:06 PM PDTHEAVY RAIN 1.014 Se Pauma Valley, CASAN LUIS REY GAGE AT OASIS MEASURED 1.01 INCHES OF RAIN BETWEEN 1703-1806 PDT.

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

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 0.5 hours before the alert went out and 60 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 00:00Z on 2012-09-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 137 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 00:00Z on 2012-09-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 67 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
137 J/kg
Mixed-layer CIN
-379 J/kg
Mixed-layer LCL
1160 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
67 m²/s²
0-3 km storm-relative helicity
107 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.

558 
WGUS56 KSGX 100030
FFWSGX
CAC073-100230-
/O.NEW.KSGX.FF.W.0040.120910T0030Z-120910T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
530 PM PDT SUN SEP 9 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

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

* UNTIL 730 PM PDT

* AT 524 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  HEAVY RAIN CAPABLE OF PRODUCING FLASH FLOODING FROM A STORM NEAR   
  PAUMA VALLEY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO PAUMA      
  VALLEY AND PORTIONS OF HIGHWAY 76 BETWEEN LAKE HENSHAW AND PAUMA   
  VALLEY.  

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 3331 11700 3334 11680 3324 11678 3322 11697

$$

JAD
2 follow-up statements
604 
WGUS76 KSGX 100056
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
556 PM PDT SUN SEP 9 2012

CAC073-100230-
/O.CON.KSGX.FF.W.0040.000000T0000Z-120910T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-
556 PM PDT SUN SEP 9 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM PDT FOR NORTH
CENTRAL SAN DIEGO COUNTY...

AT 549 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE HEAVY RAIN PRODUCING FLASH FLOODING OVER THE WARNED AREA.

RADAR ESTIMATES RAINFALL OF BETWEEN 1.5 AND 1.75 INCHES BETWEEN 4:45 
AND 5:45 PM PDT. THIS VERY HEAVY RAIN IS LIKELY PRODUCING FLASH 
FLOODING OF LOW LYING AREAS ALONG AND JUST SOUTH OF STATE ROUTE 76 
BETWEEN PAUMA VALLEY AND LAKE HENSHAW.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

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 3331 11700 3334 11680 3324 11678 3322 11697

$$

JAD
773 
WGUS76 KSGX 100214
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
714 PM PDT SUN SEP 9 2012

CAC073-100219-
/O.CAN.KSGX.FF.W.0040.000000T0000Z-120910T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-
714 PM PDT SUN SEP 9 2012

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

THE STRONG THUNDERSTORM HAS DISSIPATED SO THE FLASH FLOOD WARNING 
HAS BEEN CANCELLED. 

PEA SIZED HAIL ALONG WITH STRONG GUSTY WINDS WERE REPORTED WITH THE 
STORM. BRIEF TORRENTIAL RAINFALL RESULTED IN CARS PULLING OVER TO 
THE SHOULDER DUE TO NEAR ZERO VISIBILITY. THERE WAS ALSO FREQUENT 
LIGHTNING.  

LAT...LON 3331 11700 3334 11680 3324 11678 3322 11697

$$

SMALL

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 9, 5:23 PM PDTSevere Thunderstorm WarningSGXSan Diego45 min
Sep 9, 7:01 PM PDTFlash Flood WatchSGXRiverside, San Bernardino, San Diego23 hr
Sep 9, 7:26 PM PDTBlowing Dust AdvisorySGXRiverside, San Diego3 hr
Sep 10, 12:21 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino119 min
Sep 10, 1:17 PM PDTSevere Thunderstorm WarningSGXRiverside49 min
Sep 10, 1:29 PM PDTFlash Flood WarningSGXSan Bernardino3 hr
Sep 10, 2:00 PM PDTAreal Flood AdvisorySGXSan Bernardino3 hr
Sep 10, 2:33 PM PDTSevere Thunderstorm WarningSGXOrange, Riverside50 min
Sep 10, 2:42 PM PDTFlash Flood WarningSGXSan Diego93 min
Sep 10, 2:59 PM PDTFlash Flood WarningSGXSan Bernardino2 hr
Sep 10, 3:07 PM PDTSpecial Weather StatementSGXOrange53 min
Sep 10, 4:34 PM PDTAreal Flood AdvisorySGXSan Bernardino116 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.