Alert archive / California / Flash Flood Warnings in 2008

Flash Flood Warning 39, NWS San Diego, CA

August 4, 2008San Diego County, California

NWS San Diego, CA issued this flash flood warning at Aug 4, 2008, 1:39 PM PDT for San Diego County, California. It was in force for 111 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
Aug 4, 2008, 1:39 PM PDT (20:39 UTC)
Expired
Aug 4, 2008, 3:30 PM PDT
In force
111 min
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

County San Diego County, CA

The nearest sounding before it

San Diego, CA (KNKX), launched 12:00Z, 8.7 hours before the alert went out and 71 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 2008-08-04Temperature 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 2008-08-04The 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2165 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
67 m²/s²
0-3 km storm-relative helicity
60 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.

000 
WGUS56 KSGX 042039
FFWSGX
CAC073-042230-
/O.NEW.KSGX.FF.W.0039.080804T2039Z-080804T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
139 PM PDT MON AUG 4 2008

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

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

* UNTIL 330 PM PDT

* AT 130 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM 6 MILES NORTH OF MOUNT LAGUNA...
  OR 21 MILES SOUTH OF BORREGO SPRINGS...MOVING NORTH AT 5 MPH.

* FLASH FLOODING IS LIKELY IN SECTIONS OF MOUNT LAGUNA...AND ON
  SUNRISE HIGHWAY AND HIGHWAY S2. 

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 3302 11655 3302 11633 3284 11633 3284 11655

$$

MOEDE
3 follow-up statements
000 
WGUS76 KSGX 042111
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
211 PM PDT MON AUG 4 2008

CAC073-042230-
/O.CON.KSGX.FF.W.0039.000000T0000Z-080804T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-
211 PM PDT MON AUG 4 2008

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 PM PDT FOR
CENTRAL SAN DIEGO COUNTY...

AT 202 PM PDT...A THUNDERSTORM WITH TORRENTIAL RAIN WAS 2 MILES
EAST OF MOUNT LAGUNA. THIS STORM WAS MOVING NORTH AT 5 MPH...AND
WILL BRING FLASH FLOODING ALONG SUNRISE HIGHWAY AND THEN TO HIGHWAY 
S2 AS IT MOVES INTO EASTERN SLOPES OF THE MOUNTAINS INTO THE DESERTS.
FLOODING IS ALSO POSSIBLE IN SHELTER VALLEY AND ALONG HIGHWAY 78. 

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. WHEN ENCOUNTERING FLOODED
ROADS...TURN AROUND...DONT DROWN.

LAT...LON 3302 11655 3302 11633 3284 11633 3284 11655

$$

MOEDE
000 
WGUS76 KSGX 042157
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
257 PM PDT MON AUG 4 2008

CAC073-042230-
/O.CON.KSGX.FF.W.0039.000000T0000Z-080804T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-
257 PM PDT MON AUG 4 2008

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 PM PDT FOR
CENTRAL SAN DIEGO COUNTY...

AT 242 PM PDT...NATIONAL WEATHER SERVICE RADAR SHOWED A LINE
OF THUNDERSTORMS EXTENDING FROM MOUNT LAGUNA NORTHWARD TO BORREGO 
SPRINGS. THE STORMS HAVE DECREASED IN COVERAGE SINCE 230 PM...BUT 
HEAVY RAIN IS STILL POSSIBLE THROUGH 330 PM. 

LOW LYING SECTIONS OF HIGHWAY 78 AND HIGHWAY S3 SOUTH OF BORREGO
SPRINGS WILL BE PARTICULARLY SUSCEPTIBLE TO FLASH FLOODING. 

IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS
FLOODED ROADS.

LAT...LON 3302 11655 3302 11633 3284 11633 3284 11655

$$

MOEDE
000 
WGUS76 KSGX 042231
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
331 PM PDT MON AUG 4 2008

CAC073-042238-
/O.EXP.KSGX.FF.W.0039.000000T0000Z-080804T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-
331 PM PDT MON AUG 4 2008

...THE FLASH FLOOD WARNING WILL EXPIRE AT 330 PM PDT FOR CENTRAL SAN
DIEGO COUNTY...

THUNDERSTORMS HAVE WEAKENED...REDUCING THE THREAT FOR FLASH FLOODING.
MORE DEVELOPMENT IS POSSIBLE THROUGH THE REST OF THE AFTERNOON. 

LAT...LON 3302 11655 3302 11633 3284 11633 3284 11655

$$

MOEDE

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 3:01 AM PDTFlash Flood WatchSGXRiverside, San Bernardino, San Diego16 hr
Aug 4, 1:55 PM PDTFlash Flood WarningSGXRiverside95 min
Aug 4, 2:53 PM PDTSevere Thunderstorm WarningSGXRiverside52 min

Nearby

Flash Flood Warnings in California, 2008Every flash flood warning in 2008

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.