A powerful Pacific storm brought more heavy rain, snow and flash flooding to Central and Southern California. Total rainfall amounts ranged from 1 to 3 inches on the coastal plain to between 3 and 6 inches in the mountains.
Every event with a place to put it; 5 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 LOX wrote it up.
A powerful Pacific storm brought more heavy rain, snow and flash flooding to Central and Southern California. Total rainfall amounts ranged from 1 to 3 inches on the coastal plain to between 3 and 6 inches in the mountains. The heavy rain resulted in numerous reports of urban and rural flooding. Flash flooding closed Highway 101 at Gaviota. In Lopez Canyon near Paso Robles, a 62 year old man was swept down a flooded creek and was presumed dead. In the mountains of Ventura and Los Angeles counties, snow levels dropped to around 4500 feet, resulting in snow accumulations between 8 and 16 inches. Gusty south to southeast winds between 25 and 40 mph produced mountain visibilities near zero in blowing snow.
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 Los Angeles, CA wrote its last area forecast discussion before the first event at Dec 30, 4:00 AM PST, 6 hours earlier.
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 400 AM PST THU DEC 30 2004 .SHORT TERM...THE PERSISTENT RIDGE ALOFT THAT GAVE US ALL THE BEAUTIFUL...DRY WEATHER LAST WEEK HAS BEEN REPLACED BY AN EQUALLY PERSISTENT...WET UPPER TROUGH PATTERN THAT NAILED THE SOUTHLAND TUESDAY AND WEDNESDAY WITH RECORD FLOODING RAINS...DAMAGING WINDS... AND KNEE DEEP SNOWS IN THE MOUNTAINS. WE EXPECT THIS TROUGH TO LINGER THROUGH EARLY NEXT WEEK BEFORE WE SEE MUCH IN THE WAY OF A DRYING TREND. THEREFORE...LOOK FOR MOSTLY CLOUDY SKIES...PERIODS OF RAIN...WITH LITTLE DAY TO DAY CHANGE IN TEMPERATURES FROM NOW THROUGH TUESDAY. AS THE UPPER LOW CONTINUES ITS SPIN OFF THE WEST COAST OF THE US...IT WILL SEND SEVERAL STORMS OUR WAY OVER THE NEXT 7 DAYS. THE FIRST STORM HAS ALREADY MADE ITS WAY INTO SAN LUIS OBISPO COUNTY THIS MORNING WHERE ALMOST AN INCH OF RAIN HAS BEEN RECORDED AT ROCKY BUTTE. SCATTERED SHOWERS WILL CONTINUE OVER SAN LUIS OBISPO COUNTY THROUGH TODAY AND MOVE ACROSS SANTA BARBARA COUNTY BY THIS AFTERNOON. RAIN- FALL ACCUMULATIONS ALONG THE CENTRAL COAST SHOULD BE IN THE 1 TO 3 INCH RANGE...PERHAPS A BIT HIGHER IN SAN LUIS OBSIPO COUNTY. RAIN SHOULD REACH VENTURA COUNTY THIS AFTERNOON AND OVERSPREAD THE COUNTY DURING THE EVENING HOURS. RAIN WILL DEVELOP OVER LOS ANGELES COUNTY LATE EVENING OR OVERNIGHT. ON FRIDAY...LOOK FOR MODERATE RAIN TO MOVE ACROSS SOUTHERN CALIFORNIA DURING THE DAY...WHILE SHOWERS WILL DIMINISH OVER THE CENTRAL COAST OF SAN LUIS OBISPO COUNTY AND WESTERN SANTA BARBARA COUNTY. LOOK FOR 1 TO 2 INCHES OF RAIN POSSIBLE ALONG THE SOUTH COAST WITH 2 TO 3 INCHES ALONG THE SOUTH FACING SLOPES OF THE MOUNTAINS. SNOW LEVELS SHOULD DROP TO 4500 TO 5000 FEET ON FRIDAY WITH UP TO A FOOT OF SNOW POSSIBLE IN THE MOUNTAINS. A WINTER WEATHER ADVISORY HAS BEEN ISSUED FOR THE MOUNTAINS OF VENTURA AND LOS ANGELES COUNTIES FROM 6 PM THIS EVENING THROUGH 6 PM FRIDAY. WE ARE STILL LOOKING AT A POSSIBLE BREAK IN THE RAINY WEATHER ON SATURDAY. WHILE WE ARE NOT LOOKING FOR ANY DELUGE...WE CAN EXPECT A SLIGHT CHANCE FOR SHOWERS. SO...AN UMBRELLA MAY BE PRUDENT. EXTENDED. MEDIUM RANGE MODELS AGREE THAT A SECOND...COLDER AND WETTER STORM WILL MOVE DOWN THE CENTRAL COAST LATE SATURDAY AND INTO THE SOUTHLAND SUNDAY AND MONDAY. WHILE NOT AS STRONG AS THE TUESDAY AND WEDNESDAY RECORD EVENT...THIS SYSTEM WILL LIKELY BE MUCH STRONGER THAN THE STORM ON TODAY AND FRIDAY WITH MUCH LOWER SNOW LEVELS...STRONGER WINDS...HEAVIER RAINS...AND THE POSSIBILITY FOR MORE THUNDERSTORMS && .LOX WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY (SEE LAXCWFLOX) WINTER WEATHER ADVISORY (SEE LAXWSWLOX) && DANIELSON
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
The national radar mosaic for the moment the first event began.
4 heavy rain, 2 winter storm, 1 flash flood. Local standard time, as filed.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Heavy Rain, San Luis Obispo | 2004-12-30 | 62 | Male | In Water | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2004Every state in 2004This day in weather historyWarnings in California, December 2004
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: 5430717, 5430718, 5430719, 5430722, 5430723, 5430720, 5430721.