Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 38, NWS San Diego, CA

September 4, 2012San Diego County, California

NWS San Diego, CA issued this flash flood warning at Sep 4, 2012, 3:59 PM PDT for San Diego County, California. It was in force for 81 min. 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 4, 2012, 3:59 PM PDT (22:59 UTC)
Expired
Sep 4, 2012, 5:20 PM PDT
In force
81 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), 73 km from the middle of the area, began a volume at 22:59 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, 11.0 hours before the alert went out and 88 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 2012-09-04Temperature 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, San Diego, CA at 12:00Z on 2012-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 square meters per square second.193958Sfc1 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
2730 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
12 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.

594 
WGUS56 KSGX 042259
FFWSGX
CAC073-050100-
/O.NEW.KSGX.FF.W.0038.120904T2259Z-120905T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
359 PM PDT TUE SEP 4 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

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

* UNTIL 600 PM PDT

* AT 352 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS LIKELY PRODUCING FLASH FLOODING ALONG THE DESERT
  SLOPES OF THE MOUNTAINS BETWEEN MOUNT LAGUNA AND AGUA CALIENTE
  SPRINGS. HIGHWAY S-2 NEAR AGUA CALIENTE SPRINGS COULD RECEIVE
  FLASH FLOODING FROM HEAVY RAINS AND RUNOFF FROM THE MOUNTAINS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO CANEBRAKE
  AND AGUA CALIENTE SPRINGS

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 3307 11635 3304 11610 3262 11611 3261 11627
      3284 11642

$$

MAXWELL
2 follow-up statements
459 
WGUS76 KSGX 042326
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
426 PM PDT TUE SEP 4 2012

CAC073-050100-
/O.CON.KSGX.FF.W.0038.000000T0000Z-120905T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-
426 PM PDT TUE SEP 4 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 600 PM PDT FOR
SOUTHEASTERN SAN DIEGO COUNTY...

AT 419 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE HEAVY RAIN OVER THE WARNED AREA. HEAVY RUNOFF FROM THE 
THUNDERSTORM PREVIOUSLY BETWEEN MOUNT LAGUNA AND AGUA CALIENTE 
SPRINGS WILL CONTINUE THROUGH 500 PM AND COULD RESULT IN FLOODING 
OVER HIGHWAY S-2 NEAR AGUA CALIENTE SPRINGS. OTHERWISE THUNDERSTORMS 
WITH LOCALLY HEAVY RAIN WERE ABOUT 5 MILES NORTHEAST OF AGUA 
CALIENTE ASPRINGS...NEAR JACUMBA AND JUST NORTHEAST OF LIVE OAK 
SPRINGS.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO CANEBRAKE AND
AGUA CALIENTE SPRINGS

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.

&&

LAT...LON 3307 11635 3304 11610 3262 11611 3261 11627
      3284 11642

$$

MAXWELL
537 
WGUS76 KSGX 050020
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
520 PM PDT TUE SEP 4 2012

CAC073-050029-
/O.CAN.KSGX.FF.W.0038.000000T0000Z-120905T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-
520 PM PDT TUE SEP 4 2012

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

STORMS HAVE MOVED EAST.

LAT...LON 3307 11635 3304 11610 3262 11611 3261 11627
      3284 11642

$$

PG

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 4, 2:40 PM PDTAreal Flood AdvisorySGXSan Diego51 min
Sep 4, 4:06 PM PDTAreal Flood AdvisorySGXRiverside114 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.