The first round of winter storms hit northern California Saturday, Dec. 15th and continued into Monday evening, Dec.
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 STO wrote it up.
The first round of winter storms hit northern California Saturday, Dec. 15th and continued into Monday evening, Dec. 17th. Snow accumulations were 1/2 to 1 ft for the northern and Sierra mountains, with winds gusting up to 60mph for the mountains. Snow levels ranged 500-1500 ft for Shasta county and above 2000 ft for the Sierra. Heavy rainfall amounts were reported to be up to 1-3 in some areas. Some thunderstorms were reported with small hail in Butte county. This system was significant because it brought snow to the Northern Sacramento Valley.
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 Sacramento, CA wrote its last area forecast discussion before the first event at Dec 15, 4:53 AM PST, 2 hours 7 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 453 AM PST SAT DEC 15 2012 .SHORT TERM DISCUSSION... NORCAL UNDER BRIEF UPPER RIDGING BETWEEN WEAK SPLIT TROUGH THAT MOVED THROUGH NORCAL ON THURSDAY AND WEAK FRONTAL BAND NOW APPROACHING THE NORTH COAST. GENERALLY CLEAR SKIES HAVE ALLOWED TEMPERATURES TO DROP IN THE CENTRAL VALLEY AGAIN THIS MORNING WITH SEVERAL VALLEY LOCATIONS ALREADY AT OR BELOW THE FREEZING MARK. SOME PATCHY FOG HAS ALSO FORMED ACROSS THE VALLEY THIS MORNING. AT THIS TIME...TEMPERATURES ARE RUNNING NEAR OR JUST A BIT LOWER THAN 24 HOURS AGO. EUREKA RADAR ALREADY PICKING UP LIGHT ECHOS OFF THE NORTH COAST AS THE INCOMING SYSTEM APPROACHES. MODELS CONSIST ANT IN BRINGING THIS SYSTEM AND ITS ASSOCIATED LIGHT PRECIPITATION INLAND THIS AFTERNOON. OVERALL AIRMASS WOULD BE CONSISTENT WITH SNOW LEVELS AROUND 2000 FEET THIS AFTERNOON ACROSS THE NORTHERN ZONES. COLD TRAPPED AIR COULD CAUSE SOME ISSUES HOWEVER CREATING POCKETS OF LOWER SNOW LEVELS. BUFKIT DATA IS INDICATING THAT THERE MIGHT EVEN BE LIGHT SNOW DOWN TO THE VALLEY FLOOR ACROSS THE NORTHERN SACRAMENTO VALLEY. GOOD NEWS IS THAT THIS SYSTEM IS MOVING INTO SOME FAIRLY DRY AIR...TPW LESS THAN 1/2 INCH...SO ANY PRECIP THAT DOES FALL THIS AFTERNOON IS EXPECTED TO BE FAIRLY LIGHT. CURRENT FORECAST PACKAGE KEEPS SNOWFALL AMOUNTS BETWEEN THIS AFTERNOON AND SUNDAY MORNING AT BELOW ADVISORY CRITERIA MOST LOCATIONS. THEREFORE...WILL HANDLE LOW SNOW LEVELS AND LIGHT SNOW WITH A CONTINUATION OF THE CURRENT SPECIAL WEATHER STATEMENT. UPPER RIDGING SLIDING OVER THE WEST COAST WILL BRING UP SNOW LEVELS SOMEWHAT ON SUNDAY BUT A SHORTWAVE RIDING UP OVER THIS FAIRLY FLAT RIDGE AND INTO THE PACIFIC NORTHWEST WILL BRING A CONTINUE THREAT OF RELATIVELY LIGHT PRECIP TO THE REGION ON SUNDAY. SHORTWAVE TROUGHS BEING BROUGHT TO THE NORTH COAST BY A 150 PLUS KNOT PACIFIC JET STREAM WILL CONTINUE TO HIT THE COAST ON MONDAY. UPPER JET CORE POSITION OVER NORCAL/OREGON BORDER WILL PROVIDE MORE LIFT FOR A LITTLE BETTER PRECIP POTENTIAL BUT AIRMASS REMAINS RELATIVELY DRY. THEREFORE...NOT EXPECTING ESPECIALLY HEAVY PRECIP ON MONDAY. FLAT UPPER RIDGE BREAKS DOWN ON MONDAY AS A MORE SIGNIFICANT PACIFIC TROUGH PUSHES ON TO THE WEST COAST. AGAIN A DRY AIRMASS WILL LIMIT PRECIPITATION BUT THIS VERY COLD SYSTEM WILL BRING SNOW LEVELS DOWN TO QUITE LOW LEVELS. CURRENT PROJECTIONS ARE THAT SNOW LEVELS WILL RANGE BETWEEN 1000 AND 2000 FEET SO FOOTHILL AND EVEN SOME VALLEY LOCATIONS COULD SEE SNOWFALL GOING INTO THE MIDDLE OF THE WEEK. .EXTENDED DISCUSSION (WEDNESDAY THROUGH SATURDAY) SHOWERS DECREASE AND COLDER AIR FILTERS INTO THE AREA LATE TUESDAY AS THE TROUGH MOVES EAST OF THE AREA AND DRIER NORTHERLY LOW-LEVEL FLOW SETS UP AT THE SURFACE. VALLEY TEMPERATURES WILL BE COOL BUT NOT UNUSUALLY COLD AS THE AIRMASS WILL BE MORE MODIFIED BY THE TIME IT DESCENDS INTO THE LOWER ELEVATIONS. AREAS NEAR OR EAST OF THE SIERRA CREST HOWEVER WILL BE SUBJECTED TO THE TRUE COLD AIRMASS...WITH OVERNIGHT LOW TEENS AND SINGLE DIGITS POSSIBLE IN THE LAKE ALMANOR AREA PER CURRENT GUIDANCE. A BRIEF BREAK IS EXPECTED WEDNESDAY INTO THURSDAY AS A RIDGE QUICKLY PUSHES INTO THE WEST COAST. AS A RESULT...AT LEAST ONE NIGHT IF NOT SEVERAL OF WIDESPREAD VALLEY FOG CAN BE EXPECTED. ALOFT...ANOTHER TROUGH DIGS OFFSHORE OVER THE EASTERN PACIFIC FROM MIDWEEK THROUGH THE END OF THE WEEK. LATEST MODEL TRENDS HAVE BEEN TO AMPLIFY THE TROUGH AND SLOW DOWN ITS PROGRESSION...SO IMPACTS FOR NORCAL MAY HOLD OFF UNTIL THE WEEKEND. HAVE KEPT A BROAD CHANCE OF PRECIP IN THE FORECAST FRIDAY/SATURDAY WITH LIMITED CONFIDENCE IN TIMING OF TROUGH ARRIVAL TO OUR AREA. SNOW LEVELS LOOK TO BE HIGHER THAN THE MIDWEEK STORM. -DVC && .AVIATION... POCKETS OF IFR/LIFR FOG HAVE DEVELOPED THIS MORNING IN THE CENTRAL VALLEY AND SURROUNDING MOUNTAIN BASINS. CENTRAL VALLEY FOG LOOKS TO BE THICKEST CLOSE TO THE SACRAMENTO AND SAN JOAQUIN RIVERS. FOG SHOULD BEGIN TO DISSIPATE BY MID-MORNING. THE NEXT WEATHER SYSTEM WILL MOVE ACROSS THE REGION AFTER 18Z SATURDAY. MUCH LOWER SNOW LEVELS ARE EXPECTED...AROUND 2000FT AND POTENTIALLY LOWER IN THE KRDD VICINITY. FOR NORTHERN SAC VALLEY TAF SITES...LOOK FOR MVFR CIGS WITH -SHRA IN THE AFTERNOON. SAC METRO TAF SITES MEANWHILE EXPECTED TO REMAIN VFR. WINDS WILL REMAIN GENERALLY LIGHT...BELOW 10 KT. -DVC && .STO WATCHES/WARNINGS/ADVISORIES... NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SACRAMENTO CA 700 AM PST SAT DEC 15 2012 CAZ013>019-063-064-066>069-161500- SHASTA LAKE AREA/NORTHERN SHASTA COUNTY- BURNEY BASIN/EASTERN SHASTA COUNTY-NORTHERN SACRAMENTO VALLEY- CENTRAL SACRAMENTO VALLEY-SOUTHERN SACRAMENTO VALLEY- CARQUINEZ STRAIT AND DELTA-NORTHERN SAN JOAQUIN VALLEY- MOUNTAINS SOUTHWESTERN SHASTA TO NORTHERN LAKE COUNTIES- CLEAR LAKE/SOUTHERN LAKE COUNTY-MOTHERLODE- EAST FOOTHILLS/NORTH SACRAMENTO VALLEY- WESTERN PLUMAS COUNTY/LASSEN PARK-WEST SLOPE NORTHERN SIERRA NEVADA- 700 AM PST SAT DEC 15 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR INTERIOR NORTHERN CALIFORNIA. .DAY ONE...TODAY A PACIFIC FRONTAL SYSTEM MOVING THROUGH NORTHERN CALIFORNIA TODAY AND TONIGHT WILL BRING SEVERAL INCHES OF SNOWFALL TO THE MOUNTAINS. SNOW LEVELS WILL RANGE FROM 2000 FEET OVER THE SHASTA COUNTY MOUNTAINS TO AROUND 4000 FEET OVER THE NORTHERN SIERRA SOUTH OF INTERSTATE 80. LOCALLY LOWER SNOW LEVELS WILL BE POSSIBLE OVER THE NORTHERN SACRAMENTO VALLEY. UP TO 6 INCHES OF SNOW ARE FORECAST FOR THE SHASTA COUNTY MOUNTAINS WITH 4-10 INCHES POSSIBLE OVER THE SIERRA. * SPECIAL WEATHER STATEMENT..SEE WWUS86 KSTO - SPSSTO FOR DETAILS * .DAYS TWO THROUGH SEVEN... SUNDAY THROUGH FRIDAY LIGHT AMOUNTS OF SNOW WILL BE POSSIBLE OVER THE HIGHER ELEVATIONS THROUGH WEDNESDAY. OTHERWISE...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS TO THEIR LOCAL NATIONAL WEATHER SERVICE OFFICE. THE LATEST WEATHER INFORMATION IS AVAILABLE ON THE INTERNET AT (LOWER CASE): HTTP://WWW.WRH.NOAA.GOV/STO
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SACRAMENTO CA 537 AM PST SAT DEC 15 2012 CAZ013>015-063-064-066>069-160145- SHASTA LAKE AREA / NORTHERN SHASTA COUNTY- BURNEY BASIN / EASTERN SHASTA COUNTY-NORTHERN SACRAMENTO VALLEY- MOUNTAINS SOUTHWESTERN SHASTA COUNTY TO NORTHERN LAKE COUNTY- CLEAR LAKE/SOUTHERN LAKE COUNTY- NORTHEAST FOOTHILLS/SACRAMENTO VALLEY-MOTHERLODE- WESTERN PLUMAS COUNTY/LASSEN PARK- WEST SLOPE NORTHERN SIERRA NEVADA- 537 AM PST SAT DEC 15 2012 ...SNOW DOWN TO THE FOOTHILLS AND POSSIBLY INTO THE NORTHERN SACRAMENTO VALLEY THIS WEEKEND... A PACIFIC FRONT WILL BRING THE LIKELIHOOD OF PRECIPITATION OVER INTERIOR NORTHERN CALIFORNIA LATER TODAY AND SUNDAY. PERIODS OF MAINLY LIGHT SNOW CAN BE EXPECTED OVER THE MOUNTAINS OF SHASTA AND WESTERN PLUMAS COUNTIES AND IN THE COASTAL RANGE BEGINNING ABOUT MIDDAY TODAY AND CONTINUING INTO SUNDAY. WITH COLDER AIR ALREADY IN PLACE...SOME SNOW WILL LIKELY BE SEEN IN THE FOOTHILLS AND POSSIBLY EVEN DOWN INTO THE REDDING AREA. ONLY SMALL ACCUMULATIONS OF SNOW ARE EXPECTED AT THE LOWER ELEVATIONS AND EVEN THE HIGHER ELEVATION MOUNTAINS WILL SEE ONLY A FEW INCHES OF SNOWFALL. IN THE NORTHERN AND COASTAL MOUNTAINS...INCLUDING THE NORTHEAST FOOTHILLS AND MOUNTAINS OF WESTERN PLUMAS COUNTY...SNOW LEVELS ARE FORECAST TO BE GENERALLY AROUND 2000 TO 3000 FEET THIS AFTERNOON AND TONIGHT. LOCALLY LOWER SNOW LEVELS WILL BE POSSIBLE HOWEVER IN VALLEYS WHERE COLD AIR HAS BECOME TRAPPED. ISOLATED AREAS OF SNOW DOWN TO 1000 FEET ARE LIKELY WITH A SLIGHT POSSIBILITY OF LIGHT SNOW DOWN TO PORTIONS OF THE REDDING AREA. FOR THE WEST SLOPES OF THE NORTHERN SIERRA NEVADA..SNOW LEVELS ARE FORECAST BETWEEN 2500 AND 3500 FEET LATE TODAY INTO EARLY SUNDAY. AS WARMER AIR MOVES INTO INTERIOR NORTHERN CALIFORNIA...SNOW LEVELS WILL RISE ON SUNDAY TO ABOVE THE FOOTHILL LOCATIONS. SNOW ACCUMULATIONS OF UP TO 6 INCHES WILL BE POSSIBLE OVER THE HIGHER ELEVATIONS OF THE NORTHERN AND COASTAL MOUNTAINS BETWEEN LATE THIS AFTERNOON AND SUNDAY EVENING. SOME OF THE HIGHEST ELEVATIONS OF THE NORTHERN SIERRA CASCADE RANGE COULD SEE UP TO 10 INCHES OF NEW SNOWFALL DURING THIS SAME TIME FRAME. PERSONS TRAVELING INTO THE MOUNTAINS THIS WEEKEND MAY ENCOUNTER TRAVEL DELAYS AND CHAIN REQUIREMENTS. CHECK THE LATEST ROAD AND WEATHER CONDITIONS PRIOR TO DEPARTURE. ADDITIONAL SNOW IS EXPECTED IN THE MOUNTAINS MONDAY INTO TUESDAY.
1 winter weather. Local standard time, as filed.
Waves of precipitation entered northern California, bringing cold air and low snow levels. Trained spotters reported snow in the cities of Redding and Cottonwood at around 500-600 ft elevations, which is a rare event. Only light accumulations were reported...with the most being 3/4 to 1 in Redding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2012Every state in 2012This day in weather historyWarnings in California, December 2012
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: 423008.