Alert archive / California / Flash Flood Warnings in 2003

Flash Flood Warning 8, NWS San Diego, CA

August 20, 2003Riverside County, San Bernardino County, San Diego County, California

NWS San Diego, CA issued this flash flood warning at Aug 20, 2003, 2:30 PM PDT for Riverside County, San Bernardino 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 counties it named.

The facts

Issued
Aug 20, 2003, 2:30 PM PDT (21:30 UTC)
Expired
Aug 20, 2003, 4:30 PM PDT
In force
2 hr
Issued by
NWS San Diego, CA
Area
Whole counties

Counties Riverside County, CA, San Bernardino County, CA, San Diego County, CA

The radar

The Santa Ana Mts radar (KSOX), 122 km from the middle of the area, began a volume at 21:34 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, 9.5 hours before the alert went out and 145 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 2003-08-20Temperature 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 2003-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 71 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
1174 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
61 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 202131
FFWSGX
CAC065-071-073-202330-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
230 PM PDT WED AUG 20 2003

THE NATIONAL WEATHER SERVICE HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  WESTERN RIVERSIDE COUNTY IN SOUTHWEST CALIFORNIA
  THIS INCLUDES PALM CANYON AND THE CITIES OF...PALM SPRINGS...PALM
  DESERT...IDYLLWILD
  SOUTH CENTRAL SAN BERNARDINO COUNTY IN SOUTHWEST CALIFORNIA
  THIS INCLUDES YUCCA VALLEY
  EASTERN SAN DIEGO COUNTY IN SOUTHWEST CALIFORNIA
  THIS INCLUDES MOUNT LAGUNA AND OCOTILLO WELLS

* UNTIL 430 PM PDT

* AT 230 PM PDT...WEATHER SERVICE DOPPLER RADAR INDICATED VERY
  HEAVY RAIN OVER PARTS OF THE MOUNTAINS AND DESERTS OF SAN
  BERNARDINO...RIVERSIDE AND SAN DIEGO COUNTIES.

THE HEAVIEST RAINFALL AT 230 PM WAS FROM MOUNT LAGUNA SOUTH TO THE 
MEXICAN BORDER IN SAN DIEGO COUNTY AND ABOVE PALM CANYON IN 
RIVERSIDE COUNTY. THUNDERSTORMS WILL MOVE SLOWLY TO THE NORTH AT 10 
MPH...AND THE SLOW MOVEMENT WILL ONLY ADD TO FLOODING.

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. IF YOUR VEHICLE STALLS, ABANDON IT IMMEDIATELY AND SEEK 
HIGHER GROUND.

TO REPORT SEVERE WEATHER HAVE THE NEAREST LAW ENFORCEMENT AGENCY
RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE.

$$

LAT...LON 3268 11661 3260 11644 3263 11609 3418 11616
          3417 11693 3376 11682 3348 11696 3330 11678

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 12:27 PM PDTFlash Flood WarningSGXSan Bernardino2 hr
Aug 20, 1:04 PM PDTFlash Flood WarningSGXRiverside, San Diego86 min
Aug 20, 3:09 PM PDTSevere Thunderstorm WarningSGXSan Diego51 min

Nearby

Flash Flood Warnings in California, 2003Every flash flood warning in 2003

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.