Alert archive / California / Flash Flood Warnings in 2004

Flash Flood Warning 76, NWS San Diego, CA

October 20, 2004Orange County, California

NWS San Diego, CA issued this flash flood warning at Oct 20, 2004, 4:00 AM PDT for Orange County, California. It was in force for 3 hr. 5 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
Oct 20, 2004, 4:00 AM PDT (11:00 UTC)
Expired
Oct 20, 2004, 7:00 AM PDT
In force
3 hr
Issued by
NWS San Diego, CA
Area
Counties, with a storm outline in the text

County Orange County, CA

The radar

The Santa Ana Mts radar (KSOX), 21 km from the middle of the area, began a volume at 10:59 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.

What was reported inside it

TimeReportWhereRemark
Oct 20, 4:40 AM PDTFLASH FLOODTustin, CAHWY 91 FLOODED AT TUSTIN AV. OFFRAMP. WATER 4-5 FT. DEEP IN ONE LANDE. VEHICLES STRANDED. RAMP FROM 91 TO NORTHBOUND HWY 55 CLOSED TO SEVERE FLOODING.
Oct 20, 5:13 AM PDTFLASH FLOODSanta Ana, CAMAJOR FLOODING ON NORTHBOUND I-5 AT 1ST ST.
Oct 20, 5:45 AM PDTFLASH FLOODTustin, CANORTHBOUND HWY 55 AT 4TH ST. FLOODED. FIVE VEHICLES SUBMERGED.
Oct 20, 6:30 AM PDTFLASH FLOODSanta Ana, CANUMEROUS FREEWAY RAMPS CLOSED BECAUSE OF FLOODING. I-5 TO HWY 22 AT 518 AM. HWY 22 CLOSED ALL AROUND I-5 AND HWY 57. HWY 91 OFFRAMP AT TUSTIN CLOSED AT 535 AM. FAIRVIEW ONRAMP AT HWY 73 CLOSED AT 630 AM.
Oct 20, 7:07 AM PDTFLASH FLOODLaguna Hills, CASIX INCHES OF WATER IN LANES OF NORTHBOUND I-5 AT ALICIA PKWY.

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, 11.0 hours before the alert went out and 116 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 2004-10-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 26 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 00:00Z on 2004-10-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 110 square meters per square second.1939587897Sfc1 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
26 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
639 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
110 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS56 KSGX 201106
FFWSGX
CAC059-201400-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
400 AM PDT WED OCT 20 2004

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  ORANGE COUNTY IN SOUTHWEST CALIFORNIA
  THIS INCLUDES THE CITIES OF...YORBA LINDA...WESTMINSTER...TUSTIN
  FOOTHILLS...TUSTIN...STANTON...SEAL BEACH...SANTA ANA...SAN JUAN
  CAPISTRANO...PLACENTIA...ORANGE...MISSION VIEJO...LAGUNA NIGUEL...
  LAGUNA HILLS...LAGUNA BEACH...IRVINE...GARDEN GROVE...FOUNTAIN
  VALLEY...EL TORO...COSTA MESA...ANAHEIM

* UNTIL 700 AM PDT

* AT 355 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR             
  INDICATED FLASH FLOODING FROM A BAND OF HEAVY SHOWERS MOVING
  INTO ORANGE COUNTY FROM THE NORTHWEST. THE BAND OF SHOWERS WAS     
  MOVING SOUTHEAST AT 10 MPH.

* THE HEAVY SHOWERS PRODUCING FLASH FLOODING WILL BE NEAR...         
  SILVERADO CANYON AND 9 MILES SOUTHEAST OF YORBA LINDA BY 410 AM    
  PDT AND NEAR SANTIAGO PEAK BY 425 AM PDT

MUD SLIDES AND ROCK SLIDES ARE EXPECTED WITH THIS STORM. MUD SLIDES
AND ROCK SLIDES CAN POTENTIALLY TRAP AND KILL PEOPLE CAUGHT IN THEIR
PATH.

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.

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 3375 11810 3344 11762 3366 11744 3394 11784

$$

HORTON

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 19, 11:50 PM PDTFlash Flood WarningSGXSan Bernardino6 hr
Oct 20, 6:15 AM PDTFlash Flood WarningSGXOrange, Riverside, San Bernardino, San Diego3 hr
Oct 20, 9:00 AM PDTFlash Flood WarningSGXOrange, Riverside, San Bernardino, San Diego2 hr
Oct 20, 10:38 AM PDTFlash Flood WarningSGXRiverside, San Bernardino, San Diego2 hr
Oct 20, 1:00 PM PDTFlash Flood WarningSGXSan Diego2 hr
Oct 20, 3:00 PM PDTFlash Flood WarningSGXSan Diego4 hr

Nearby

Flash Flood Warnings in California, 2004Every flash flood warning in 2004

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.