More than an inch of rain in less than an hour caused mud and rock slides, and urban flooding.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS SGX wrote it up.
More than an inch of rain in less than an hour caused mud and rock slides, and urban flooding.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS San Diego, CA wrote its last area forecast discussion before the first event at Aug 1, 9:00 AM PST, 3 hours earlier.
EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN DIEGO CALIFORNIA 1000 AM PDT FRI AUG 1 2003 .SYNOPSIS...A TROUGH OF LOW PRESSURE OFF THE COAST OF SOUTHERN CALIFORNIA WILL MOVE NORTHEASTWARD ACROSS SOUTHERN CALIFORNIA TODAY. THUNDERSTORMS OVER THE MOUNTAINS AND DESERTS TODAY COULD HAVE LOCALLY HEAVY RAINFALL. DRY SOUTHWEST FLOW SHOULD GRADUALLY RETURN BY EARLY NEXT WEEK WITH DECREASING THUNDERSTORMS OVER THE MOUNTAINS AND INCREASING COASTAL LOW CLOUDS. .DISCUSSION...FLASH FLOOD WATCH THROUGH 9 PM PDT TODAY FOR THE SAN BERNARDINO MOUNTAINS AND APPLE AND YUCCA VALLEY AREAS. SEE LAXFFASGX FOR DETAILS. SOME HEAVY SHOWERS OCCURRED NEAR PALM SPRINGS IN THE PAST COUPLE HOURS. AREA UNDER SOUTHWESTERN EDGE OF THE CLOUD SHIELD COVERING MUCH OF THE EASTERN DESERTS. CLOUDS ARE MOVING NORTHWEST BUT AREA APPEARS TO BE SHIFTING A LITTLE TO THE NORTH IN RESPONSE TO THE SHORTWAVE TROUGH SLIDING NORTHEAST OFF THE COAST. DOPPLER RADAR INDICATES MOST OF THE MOISTURE IS WELL NORTH AND EAST OF OUR AREA BUT AREA REMAINS RIPE FOR CONVECTION OVER THE MOUNTAINS AND DESERTS ESPECIALLY WITH THE SHORTWAVE SLIDING BY. IDEA OF THE FLASH FLOOD WATCH APPEARS GOOD. MIGHT HAVE TO ADJUST IT TO INCLUDE THE RIVERSIDE COUNTY MOUNTAINS AS WELL AS THE COACHELLA VALLEY. COASTAL STRATUS IS ON THE DECREASE WITH THE SOUTHERN SAN DIEGO COUNTY COASTLINE THE REMAINING HOLD OUT BUT STRATUS SHOULD CLEAR OUT OF THAT AREA WITHIN THE NEXT HOUR OR TWO. 12Z ETA INDICATES THE SHORTWAVE OFF THE COAST WILL BE NORTH OF THE AREA LATE SATURDAY AND SUNDAY. THUNDERSTORMS SHOULD BE ON THE DECREASE OVER THE MOUNTAINS AND SATURDAY WITH LITTLE OR NO ACTIVITY EXPECTED ON SUNDAY. .SAN...FLASH FLOOD WATCH...SEE LAXFFASGX. HORTON
CAZ042-043-048-050-055>058-060>062-021300- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN DIEGO CA 600 AM PDT THU JUL 31 2003 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EXTREME SOUTHWESTERN CALIFORNIA. .DAY ONE... TODAY THROUGH TONIGHT A FLASH FLOOD WATCH IS IN EFFECT THROUGH 9 PM FOR THE SAN BERNARDINO MOUNTAINS AND FOR THE APPLE AND YUCCA VALLEYS. THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL ARE ALSO POSSIBLE FOR THE MOUNTAINS AND DESERTS OF SAN DIEGO AND SOUTHWESTERN RIVERSIDE COUNTIES. .DAYS TWO THROUGH SEVEN... SATURDAY THROUGH THURSDAY A CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS IN THE MOUNTAINS AND DESERTS SATURDAY. LOCALLY HEAVY RAINFALL IS POSSIBLE. MARTIN
The national radar mosaic for the moment the first event began.
1 heavy rain. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2003Every state in 2003This day in weather historyWarnings in California, August 2003
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5368346.