A powerful winter storm impacted Southern California on December 7th. The storm produced widespread moderate to heavy precipitation and strong gusty winds.
Every event with a place to put it; 9 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.
A powerful winter storm impacted Southern California on December 7th. The storm produced widespread moderate to heavy precipitation and strong gusty winds. The system had an impressive 55 kt 925 mb jet ahead of the cold front. The snow level started off relatively high, so only locations at or above the resort levels saw snowfall over one foot, while other mountain communities received a few inches. Higher elevations in the northern deserts also received a dusting of snow. Rainfall totals ranged from about one to over four inches in the coastal and valley regions, and the low deserts received up to one and one-half inches.
Much damage was reported with this storm. Rain soaked grounds and gusty winds uprooted multiple trees throughout the region, damaging vehicles and buildings. Over 100,000 customers lost power at some time during the storm.
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 Dec 7, 2:30 AM PST, 1 hour earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN DIEGO CA 230 AM PST MON DEC 7 2009 .SYNOPSIS...A STRONG PACIFIC COLD FRONT WILL MOVE ACROSS SOUTHERN CALIFORNIA TODAY THROUGH TONIGHT...BRINGING HEAVY RAIN...A LOT OF MOUNTAIN SNOW...AND STRONG WINDS. A WARMER...WEAKER COLD FRONT WILL BRING LIGHT RAIN THURSDAY INTO FRIDAY. MOSTLY CLOUDY NEXT WEEKEND WITH CHANCES OF RAIN AS A MOIST PACIFIC WARM FRONT MOVES BY MOSTLY TO THE NORTH OF THE AREA. && .DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO... ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES. A COLD 527 POSITIVE TILT TROF CONTINUES TO DEVELOP OVER N CALIF. THIS PUTS US IN STRONG MOIST 555 W FLOW ALOFT WHICH WILL CAUSE AREAS OF LIGHT...WARM-SECTOR PRECIP AS THE TROF APPROACHES THIS MORNING. THE TROF INTENSIFIES UNDER A 150 KT JET MAX...PRODUCING A LARGE... STRONG COLD FRONT...THAT WILL COME THROUGH SOCAL BETWEEN 10 AM AND 10 PM TODAY. S-SW SURFACE FLOW AND STRONG W FLOW ALOFT...ALONG WITH INSTABILITY...WILL PRODUCE HEAVY RAIN AND MT SNOW. THE WINTER STORM WARNING AND THE FLASH FLOOD WATCH LOOK GOOD. STORM TOTALS SHOULD RANGE FROM 1 TO 2 INCHES IN COASTS AND VALLEYS AND 2 TO 4 INCHES IN THE LOW ELEV MTS. THE HEAVY RAIN COULD CAUSE MUD SLIDES AND DEBRIS FLOWS IN AND BELOW RECENTLY BURNED AREAS AND ON STEEP TERRAIN. THERE MAY ALSO BE FLOODING OF POORLY DRAINED STREETS AND LOW LYING AREAS. THE SNOW LEVEL WILL BE 5500 FT THIS PM...LOWERING TO 4000 FT TONIGHT WITH 1 FT OF SNOW AT RESORT LEVEL AND 2-3 FEET AT HIGHER ELEVATIONS. EVEN SAN DIEGO MTS SHOULD GET 1/2 FT OF SNOW. STRONG SW WINDS COULD CAUSE SNOW AND BLOWING SNOW WITH NEAR BLIZZARD CONDITIONS AT TIMES. THE STRONG HELICITY AND INSTABILITY ASSOCIATED WITH THE FRONT COULD PRODUCE ISOLATED TSTORMS AND WATERSPOUTS THIS PM. WILL NOT PUT THAT IN THE GRIDS...BUT IT WILL BE SOMETHING TO WATCH FOR. BY MIDNIGHT...THE FRONT AND THE MAIN PRECIP WILL HAVE FINISHED. BUT AN INTENSE 992 MB LOW OVER NW ARIZONA WILL CAUSE 17 MB ONSHORE PRESSURE GRADIENTS. THUS HIGH WIND WARNINGS WILL CONTINUE IN THE MTS AND DES...PARTICULARLY IN SAN DIEGO COUNTY...TONIGHT INTO TUE. LINGERING SHOWERS TUE AM. PARTLY CLOUDY AND BREEZY TUE PM WITH 564 WNW FLOW ALOFT. A VERY COLD AIR MASS WILL STILL BE IN PLACE IN THE WAKE OF THE FRONT...SO FROST OR FREEZE CONDITIONS ARE POSSIBLE TUE NIGHT. WARMER AND CLEARER WED UNDER A WEAK 567 RIDGE. 564 WEST FLOW ALOFT...A WEAK COLD FRONT...AND A VERY DEEP MARINE LAYER WILL BRING PERIODS OF LIGHT RAIN OR DRIZZLE THU INTO FRI WITH 1/4 INCH OF RAIN ON THE FLATS. EXPECT SNOW LEVELS TO BE ABOVE 6000 FT WITH WITH 2-4 INCHES OF SNOW AT THE RESORTS UNDER 564 FLOW ALOFT. WARM...STRONG ZONAL FLOW PATTERN SETS UP BY THE WEEKEND...WITH A LOT OF MOISTURE STAYING NORTH OF US. LOOKS LIKE WE WILL BE ON THE DRY SOUTHERN SIDE OF THE JET STREAM UNDER MOSTLY 570 WEST FLOW ALOFT. MAY MANAGE TO GET 1/4 TO 1/2 INCH OF RAIN ON THE FLATS DUE TO THICK MID AND HIGH CLOUDS. RAIN COULD ENHANCE SNOW MELT. CLEARING AND WARMER EARLY NEXT WEEK UNDER A 580 UPPER RIDGE AND WEAK ONSHORE FLOW. && .AVIATION... 071030Z...BROKEN TO OVERCAST CLOUDS BASED 3000-4000 FT MSL MERGING WITH HIGHER LAYERS TO ABOUT 6500 FEET MSL...WILL BECOME MORE SOLID AND BASES WILL LOWER GRADUALLY INTO MIDDAY. BASES AROUND 1000-2000 FT MSL AND LOCAL VISIBILITIES 3 TO 5 MILES CAN BE EXPECTED IN HEAVIER RAIN DURING MAINLY THE LATE MORNING AND AFTERNOON. MOUNTAINS WILL BE MOSTLY OBSCURED IN CLOUDS AND PRECIPITATION...AND WILL HAVE STRONG UP AND DOWNDRAFTS AND WIND SHEAR. STRONG SOUTH TO SOUTHWEST WINDS WITH GUSTS 40 TO 50 KNOTS POSSIBLE AT KSAN. EXPECT COLD FRONTAL PASSAGE AROUND 00Z THIS AFTERNOON WITH WINDS SHIFTING TO WESTERLY. SMALL && .MARINE... A STRONG COLD FRONT WILL BRING HAZARDOUS SEAS AND WINDY CONDITIONS TODAY THROUGH TUESDAY MORNING. THERE WILL BE A GALE WARNING FOR THE INNER AND OUTER WATERS THROUGH TUESDAY MORNING. A RAPID RISE IN WESTERLY SWELL WILL ACCOMPANY THE FRONT MONDAY EVENING...THEN DECREASE EARLY TUESDAY. A HIGH RIP CURRENT RISK WILL DEVELOP THIS AFTERNOON AS SWELL AND SURF RISE RAPIDLY. && .SGX WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING...SEE LAXWSWSGX. HIGH WIND WARNING...SEE LAXNPWSGX. GALE WARNING...SEE LAXMWWSGX. FLASH FLOOD WATCH...SEE LAXFFASGX. && PUBLIC...MACKECHNIE AVIATION/MARINE...SMALL
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN DIEGO CA 720 PM PST SUN DEC 6 2009 CAZ042-043-048-050-055>058-060>062-PZZ750-775-071215- ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS- SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE- SAN DIEGO COUNTY VALLEYS-SAN BERNARDINO COUNTY MOUNTAINS- RIVERSIDE COUNTY MOUNTAINS-SANTA ANA MOUNTAINS AND FOOTHILLS- SAN DIEGO COUNTY MOUNTAINS-APPLE AND LUCERNE VALLEYS- COACHELLA VALLEY-SAN DIEGO COUNTY DESERTS- COASTAL WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER AND OUT 30 NM- WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING 30 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND- 720 PM PST SUN DEC 6 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST CALIFORNIA AND PZ. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY A STRONG COLD FRONT WILL MOVE ACROSS SOUTHERN CALIFORNIA MONDAY AND MONDAY NIGHT...BRINGING... * RAIN...HEAVY AT TIMES...WITH POSSIBLE FLASH FLOODING AND DEBRIS FLOWS IN AND BELOW BURN AREAS...AND LOCAL URBAN AND SMALL STREAM FLOODING. * A LOT OF MOUNTAIN SNOW ABOVE 6000 FEET...WITH A WINTER STORM WARNING IN EFFECT FOR THE SAN BERNARDINO AND RIVERSIDE COUNTY MOUNTAINS FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT... * STRONG SOUTH TO WEST WINDS...WITH GUSTS OF 60 MPH POSSIBLE. STRONGEST WINDS WILL BE WITH THE PASSAGE OF THE COLD FRONT MONDAY EVENING. * HAZARDOUS BOATING CONDITIONS FOR POSSIBLE GALE FORCE WINDS AND STEEP SEAS IN THE INNER AND OUTER WATERS FROM MID MORNING MONDAY THROUGH LATE MONDAY NIGHT... * ABOVE NORMAL SURF AT THE BEACHES LATE MONDAY THROUGH TUESDAY WITH SOME SETS WELL OVER 6 FEET. A WARMER STORM COULD BRING MODERATE AMOUNTS OF RAIN ON THURSDAY OR THURSDAY NIGHT. .SPOTTER INFORMATION STATEMENT...SKYWARN WEATHER ACTIVATION IS NOT REQUESTED FOR THIS AREA TONIGHT BUT MAY BE NEEDED ON MONDAY. JAD/MAXWELL
The national radar mosaic for the moment the first event began.
5 high wind, 3 strong wind, 2 heavy snow. Local standard time, as filed.
Snow began in Big Bear around 0330 PST and continued through about 1845 PST. By 1600 PST, 13 inches of snow had accumulated.
Snow began at Pine Cove around 0400 PST and continued through about 1715 PST. A trained spotter reported a storm total of 14 inches. The nearby town of Idyllwild received 10 inches of snow from the storm.
Gusty winds caused a large oak tree to fall on a car in Ramona around 1800 PST. In Scripps Ranch, a eucalyptus tree fell on a home, destroying a garage. No injuries were reported with either incident.
High winds were measured by the Julian mesonet between 1507 and 0054 PST. At 2025 PST, a peak wind gust of 71 MPH was measured. A trained spotter also measured a peak gust of 74 MPH at Cuyamaca at 1523 PST.
Heavy snow and gusty winds were responsible for knocking down two trees in the San Bernardino County mountains. The first, in Big Bear Lake, fell onto a home on Cherry Lane, causing minor damage. The second incident was in Boulder Bay, where a tree fell and did damage to two homes, knocked down power lines, and destroyed a car and a trailer.
Gusty winds knocked over trees throughout Orange County, damaging buildings and cars. In Tustin, arcing power lines caused a power pole to catch fire. No injures were reported.
A peak wind gust of 59 MPH was measured by the Point Loma mesonet between 1730 and 1745 PST. High winds ended by 1815 PST.
In Encinitas, a eucalyptus tree fell on a condo causing minor damage to the roof.
High winds were measured by the Pinyon RAWS between 1936 and 0036 PST. Between 2336 and 0036 a peak wind gust of 62 MPH was measured.
High winds occurred in the Coachella Valley between 2350 and 0750 PST. The Whitewater RAWS measured a peak wind gust of 73 MPH between 0350 and 0450 PST.
A peak wind gust of 62 MPH was measured by the Burns Canyon RAWS between 0251 and 0351 PST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2009Every state in 2009This day in weather historyWarnings in California, December 2009
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: 207478, 207479, 207484, 207476, 207481, 207483, 206893, 207475, 206903, 206897.