Another, much weaker low pressure system moved through Southern California December 29-30. The storm dropped more rain in the valleys and snow in the mountains, though not nearly to the extent of the previous week's flooding.
Every event with a place to put it; 2 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.
Another, much weaker low pressure system moved through Southern California December 29-30. The storm dropped more rain in the valleys and snow in the mountains, though not nearly to the extent of the previous week's flooding. Some gusty winds also accompanied the storm as it passed.
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 29, 3:30 AM PST, 3 hours 30 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN DIEGO CA 330 AM PST WED DEC 29 2010 .SYNOPSIS...A STRONG COLD FRONT WILL SPREAD RAIN AND MOUNTAIN SNOW ACROSS SOUTHWEST CALIFORNIA THIS MORNING. SHOWERS WILL LINGER INTO THIS EVENING. LOCAL STRONG GUSTY WINDS THROUGH TONIGHT WITH THE STRONGEST WINDS IN THE MOUNTAINS AND DESERTS. NORTHWEST FLOW ALOFT WILL KEEP THE WEATHER COLD AND DRY THURSDAY AND FRIDAY. A LITTLE WARMER SATURDAY UNDER WEAK HIGH PRESSURE. LOW PRESSURE COULD BRING MORE SHOWERS EARLY NEXT WEEK. && .DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO... ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES. .SHORT TERM (TODAY-FRIDAY)...SKIES WERE MOSTLY CLOUDY EARLY THIS MORNING. THE COLD FRONT WAS WAS STILL N OF PT CONCEPTION. AIRCRAFT SOUNDINGS SHOWED INCREASING NW WINDS ALOFT. ONSHORE GRADIENTS AND TRENDS WITH ABOUT 5 MB SAN-IPL. THE COLD FRONT WILL MOVE THROUGH SW CALIFORNIA THIS MORNING. PRECIP WILL SPREAD BEGIN IN ORANGE AND SAN BERNARDINO COUNTY AROUND 4 AM AND SPREAD S ACROSS THE AREA BY 8 AM. THERE WILL BE ABOUT A 4 TO 6 HOUR PERIOD OF MODERATE TO HEAVY PRECIP THIS MORNING. SHOWERS WILL CONTINUE BEHIND THE FRONT AND WILL GRADUALLY DECREASE FROM THE NW THROUGH THIS EVENING. RAINFALL TOTALS SHOULD RANGE FROM ABOUT A THIRD TO TWO THIRDS OF AN INCH IN THE COASTAL AND VALLEYS AREAS WITH NEAR AN INCH ON THE COASTAL MOUNTAIN SLOPES. HOWEVER...THERE COULD BE LOCAL LARGER AMOUNTS ON THE SW FACING SLOPES OF THE SAN BERNARDINO COUNTY MOUNTAINS. THE HIGH DESERTS SHOULD GET UP TO ABOUT A THIRD OF AN INCH OF RAIN WITH LESS THAN A QUARTER OF AN INCH IN THE LOWER DESERTS. THE ADDITIONAL RAINFALL WILL CAUSE RAPID RUNOFF AND FLOODING DUE TO NEARLY SATURATED GROUND FROM RECENT RAIN. THIS COULD RESULT IN FLOODING OF LOW LYING AREAS. THERE COULD BE DEBRIS FLOWS IN AND BELOW RECENTLY BURNED AREAS AS WELL AS ROCK AND MUD SLIDES ON STEEP TERRAIN...AND FURTHER EROSION OF RAIN SOAKED HILLSIDES. THE SNOW LEVEL WILL LOWER FROM 7000 FT TO 6000 FT IN THE NRN AREAS THIS MORNING...THEN LOWER RAPIDLY BEHIND THE COLD FRONT TO ABOUT 4000 FEET. HOWEVER...MOST OF THE WIDESPREAD SIGNIFICANT PRECIPITATION WILL BE OVER BY THE TIME THE SNOW LEVEL LOWERS. SAN BERNARDINO AND RIVERSIDE COUNTY MOUNTAINS COULD LOCALLY GET ABOUT 4 TO 8 INCHES OF SNOW ABOVE 6000 FT. HOWEVER...THERE COULD BE ISOLATED SNOW AMOUNTS NEAR A FOOT ON THE HIGHEST PEAKS. IF PRECIPITATION LINGERS INTO THE EVENING THERE COULD EVENTUALLY BE AN INCH OR TWO OF SNOW IN THE HIGHER SAN DIEGO COUNTY MOUNTAINS. IF PRECIP CONTINUES INTO THIS EVENING THEN LIGHT SNOW SHOWERS ARE POSSIBLE IN THE UPPER DESERTS AND INTO THE INLAND VALLEYS NEAR THE FOOTHILLS. STRONG GUSTY WINDS WILL PRECEDE AND ACCOMPANY THE FRONT. THE WINDS WILL BECOME EVEN STRONGER OUT OF THE W AND NW BEHIND THE FRONT WEDNESDAY AFTERNOON AND EVENING. THE STRONGEST WINDS WILL BE IN THE MOUNTAINS AND DESERTS WHERE THERE COULD BE LOCAL GUSTS OVER 60 MPH. NW FLOW WILL DEVELOP ALOFT THURSDAY. THIS WILL BRING DRY BUT COLDER WEATHER. MAX TEMPS WILL BE ABOUT 6 TO 12 DEGREES BELOW SEASONAL AVERAGES TODAY AND ABOUT 10 TO 20 DEGREES BELOW THURSDAY AND FRIDAY. THERE COULD BE PATCHY IN THE INLAND VALLEYS THURSDAY MORNING. FROST WILL LIKELY BE WIDESPREAD IN THE INLAND VALLEYS AND LOWER DESERTS THURSDAY NIGHT. HOWEVER...WET GROUND AND WIND MAY MITIGATE FROST DURATIONS. && .LONG TERM (SATURDAY-TUESDAY)...A WEAK UPPER RIDGE WILL BRING FAIR AND A LITTLE WARMER WEATHER SATURDAY. AN UPPER LOW SHOULD DROP S OFF THE COAST SUNDAY THROUGH TUESDAY. THIS WILL BRING VARIABLE CLOUDINESS AND SMALL CHANCES OF LIGHT PRECIP. HOWEVER...MODELS REMAIN INCONSISTENT FOR THE EXTENDED PERIOD. && .AVIATION... 291030Z...MULTIPLE CLOUD LAYERS WITH BASES AS LOW AS 1500 FT MSL WILL CONTINUE AS A BAND OF MODERATE RAIN MOVES THROUGH SOUTHERN CALIFORNIA. RAIN SHOULD REACH KSNA AND KONT BETWEEN 12Z-14Z AND SPREAD SOUTH REACHING KSAN AROUND 15Z. MOSTLY MVFR CIGS/VSBY EXPECTED WITH THE RAIN WITH LOCAL IFR/LIFR CONDITIONS IN HEAVIER SHOWERS. RAIN SHOULD TAPER OFF AROUND 21Z IN THE NORTHERN AREAS AND AROUND 00Z FURTHER SOUTH. SCATTERED LIGHT TO MODERATE SHOWERS COULD CONTINUE THROUGH THE EARLY EVENING. FEW-SCT LOW CLOUDS WILL LINGER INTO THURSDAY MORNING WITH AREAS OF GROUND FOG IN THE INLAND VALLEYS AFTER 09Z THURSDAY. GUSTY SW TO W WINDS WILL INCREASE AS THE FRONT APPROACHES AND CONTINUE THROUGH LATE TODAY. STRONGEST WINDS WILL BE IN THE MTNS AND DESERTS WHERE LOCAL GUSTS TO 55 KT ARE POSSIBLE...ALONG WITH ASSOCIATED UDDFS AND LLWS. WINDS WILL GRADUALLY WEAKEN THROUGH THURSDAY MORNING. && .MARINE... AN APPROACHING COLD FRONT WILL BRING STRONG WINDS...LARGE SWELLS AND ROUGH SEAS TO THE COASTAL WATERS THIS MORNING THROUGH THURSDAY MORNING. THE WINDS AND SWELL WILL PEAK LATE THIS EVENING WITH SUSTAINED WINDS IN EXCESS OF 20 KTS AND GUSTS OVER 30 KTS. THIS WILL LIKELY RESULT IN COMBINED SEAS OF 10 FT OR MORE. THE INCREASING SWELLS WILL ALSO BRING THE CHANCE FOR HIGH SURF ON THU. && .SGX WATCHES/WARNINGS/ADVISORIES... SPECIAL WEATHER STATEMENT. SEE LAXSPSSGX. HIGH WIND WARNING UNTIL 4 AM THURSDAY FOR THE MOUNTAINS AND UPPER DESERTS. WIND ADVISORY FOR THE COASTAL AND VALLEY AREAS 10 AM TODAY UNTIL 4 AM THURSDAY. SEE LAXNPWSGX. WINTER STORM WARNING UNTIL 8 PM WEDNESDAY FOR THE SAN BERNARDINO AND RIVERSIDE COUNTY MOUNTAINS ABOVE 6000 FT. SEE LAXWSWSGX. SMALL CRAFT ADVISORY FOR COASTAL WATERS OFF SAN DIEGO COUNTY. SEE LAXMWWSGX. && PUBLIC...ATKIN AVIATION/MARINE...SS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN DIEGO CA 400 AM PST WED DEC 29 2010 CAZ042-043-048-050-055>058-060>062-300000- 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- 400 AM PST WED DEC 29 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR ALL OF EXTREME SOUTHWESTERN CALIFORNIA. .DAY ONE...TODAY THROUGH TONIGHT A COLD FRONT WILL BRING RAIN AND MOUNTAIN SNOW...HEAVY AT TIMES. LOCAL STRONG GUSTY WINDS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY LOCAL STRONG GUSTY WINDS THURSDAY MORNING. IT WILL BE COLD WITH WIDESPREAD FROST IN THE INLAND VALLEYS AND LOWER DESERTS THURSDAY NIGHT AND FRIDAY NIGHT. .SPOTTER INFORMATION STATEMENT...SKYWARN SPOTTER ACTIVATION MAY BE NEEDED LATE TONIGHT AND WEDNESDAY. ATKIN
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SAN DIEGO CA 242 AM PST WED DEC 29 2010 CAZ042-043-048-050-055>058-060>062-292200- 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- 242 AM PST WED DEC 29 2010 ...WINTER STORM TO IMPACT SOUTHWEST CALIFORNIA TODAY FOLLOWED BY VERY COLD WEATHER... A STRONG STORM APPROACHING FROM THE NORTHWEST WILL MOVE THROUGH THIS MORNING WITH SHOWERS LINGERING THROUGH THIS EVENING. THIS FAST MOVING SYSTEM SHOULD TAP INTO DEEP MOISTURE RESULTING IN A PERIOD OF MODERATE TO HEAVY PRECIPITATION WITH THE FRONTAL PASSAGE THIS MORNING. RAINFALL TOTALS SHOULD RANGE FROM ABOUT A THIRD TO TWO THIRDS OF AN INCH IN THE COASTAL AND VALLEYS AREAS WITH NEAR AN INCH ON THE COASTAL MOUNTAIN SLOPES. HOWEVER...THERE COULD BE LOCAL LARGER AMOUNTS ON THE SOUTHWEST FACING SLOPES OF THE SAN BERNARDINO COUNTY MOUNTAINS. THE HIGH DESERTS SHOULD GET UP TO ABOUT A THIRD OF AN INCH OF RAIN WITH LESS THAN A QUARTER OF AN INCH IN THE LOWER DESERTS. THE ADDITIONAL RAINFALL WILL CAUSE RAPID RUNOFF AND FLOODING DUE TO NEARLY SATURATED GROUND FROM RECENT RAIN. THIS COULD RESULT IN FLOODING OF LOW LYING AREAS. THERE COULD BE DEBRIS FLOWS IN AND BELOW RECENTLY BURNED AREAS AS WELL AS ROCK AND MUD SLIDES ON STEEP TERRAIN...AND FURTHER EROSION OF RAIN SOAKED HILLSIDES. THE SNOW LEVEL WILL BE NEAR 7000 FEET THROUGH MOST OF THE STORM...THEN FALL TO 6000 FEET BY WEDNESDAY AFTERNOON AND TO 3000 FEET OR LOWER WITH A FEW LINGERING SHOWERS. HOWEVER...MOST OF THE WIDESPREAD SIGNIFICANT PRECIPITATION WILL BE OVER BY THE TIME THE SNOW LEVEL LOWERS...AND ANY SNOWFALL ACCUMULATIONS WILL BE VERY SMALL BELOW 5000 FEET. SAN BERNARDINO AND RIVERSIDE COUNTY MOUNTAINS WILL LOCALLY GET ABOUT ABOUT 3 TO 8 INCHES OF SNOW ABOVE 6000 FEET. HOWEVER...THERE COULD BE ISOLATED AMOUNTS TO NEAR A FOOT ABOVE 7000 FEET. THE HIGHER SAN DIEGO COUNTY MOUNTAINS COULD GET AN INCH OR TWO OF SNOW. IF SHOWERS CONTINUE INTO THE EVENING THERE COULD BE LIGHT SNOW IN THE HIGH DESERTS AND NEAR THE INLAND VALLEY FOOTHILLS. ROADS WILL BECOME ICY IN THE MOUNTAINS TONIGHT...INCLUDING THROUGH THE CAJON PASS. STRONG GUSTY WEST TO NORTHWEST WINDS WILL ACCOMPANY THIS SYSTEM...BECOMING EVEN STRONGER BEHIND THE FRONT TONIGHT. THE STRONGEST WINDS WILL BE IN THE MOUNTAINS AND HIGH DESERTS WHERE THERE COULD BE WIND GUSTS OVER 65 MPH. THESE WINDS COULD CAUSE BROKEN TREE LIMBS...DOWNED TREES AND DOWNED POWER LINES. NEAR ZERO VISIBILITY WILL BE POSSIBLE AT TIMES DUE TO SNOW AND BLOWING SNOW. DRY COLD NORTHWEST FLOW ALOFT WILL BRING TEMPERATURES ABOUT 10 TO 20 DEGREES BELOW SEASONAL AVERAGES THURSDAY AND FRIDAY. THERE WILL LIKELY BE WIDESPREAD FROST IN THE INLAND VALLEYS THURSDAY AND FRIDAY NIGHTS. PEOPLE TRAVELING LATE TUESDAY AND WEDNESDAY SHOULD CLOSELY MONITOR THE LATEST NATIONAL WEATHER SERVICE FORECASTS AND STATEMENTS AND PLAN ACCORDINGLY. THE RAIN WILL CAUSE SLICK ROADS AND MOTORISTS SHOULD USE EXTRA CAUTION. DO NOT DRIVE THROUGH FLOODED AREAS OR AROUND BARRICADES. IF TRAVELING INTO THE MOUNTAINS...BE PREPARED FOR THE POSSIBILITY OF WINTER STORM CONDITIONS WITH VERY LOW WIND CHILL TEMPERATURES. ATKIN
The national radar mosaic for the moment the first event began.
2 high wind. Local standard time, as filed.
The beginning and ending times of the high wind criteria are uncertain. The Mill Creek RAWS reported a gust of 63 MPH at 0223 PST on December 30.
The beginning and ending times for high wind criteria are uncertain. The Pinyon Pines RAWS reported a gust of 58 MPH at 0136 PST on December 20.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2010Every state in 2010This day in weather historyWarnings in California, December 2010
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: 274171, 274174.