Several days of precipitation in northeast California with moist flow off the Pacific wrapped up with a final heavy snowfall event on the 24th.
Every event with a place to put it; 3 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 REV wrote it up.
Several days of precipitation in northeast California with moist flow off the Pacific wrapped up with a final heavy snowfall event on the 24th.
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 Reno, NV wrote its last area forecast discussion before the first event at Dec 23, 2:02 PM PST, 7 hours 58 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
202 PM PST WED DEC 23 2015
.SYNOPSIS...
A COLD FAST MOVING STORM WILL BRING PERIODS OF HEAVY SNOW TO THE
SIERRA AND HEAVY SNOW SHOWERS TO WESTERN NEVADA EARLY THURSDAY
MORNING INTO THURSDAY NIGHT. SNOW COVERED ROADS AND BLOWING SNOW
ARE LIKELY ACROSS THE REGION. CLEARING AND COLD CONDITIONS FOR
CHRISTMAS DAY INTO THE WEEKEND. WHILE MOST OF NEXT WEEK APPEARS
DRY WITH A SLOW WARMING TREND, ONE OR TWO WEAK STORMS MAY IMPACT
THE AREA WITH LIGHT PRECIPITATION BUT FORECAST CERTAINTY IS LOW.
&&
.SHORT TERM...
SO WE'VE GOT A COLD WINTER STORM ON THE WAY FOR CHRISTMAS EVE. ON
THE BIG PICTURE NOT MUCH HAS CHANGED - THIS STORM HAS BEEN IN THE
MODELS FOR NEARLY A WEEK! A COMBINATION OF A COLD UNSTABLE
AIRMASS WITH SHORTWAVE ENERGY ALOFT WILL HELP CREATE HIGH-RATIO
MOUNTAIN SNOWS AND HEAVY SNOW SHOWERS IN THE VALLEYS ROUGHLY
9Z/THURSDAY THROUGH 6Z/FRIDAY. SOME SPECIFIC ISSUES TO ADDRESS...
TIMING - GUIDANCE IS COMING IN ABOUT 3 HOURS FASTER FOR THE
SPILLOVER INTO WESTERN NEVADA SO HAVE STARTED THE ADVISORIES
EARLIER AT 7 AM THURSDAY. THIS INCREASES IMPACTS TO TRAVELERS AND
ANYONE STILL HEADING INTO WORK.
SNOW AMOUNT VARIABILITY - WHILE THE QPF FORECAST FOR THE SIERRA IS
FAIRLY CONSISTENT BETWEEN THE MOST RECENT NAM/GFS SIMULATIONS, THERE
ARE SOME APPRECIABLE DIFFERENCES FOR WESTERN NEVADA AND EAST OF
395 IN CALIFORNIA. WHAT ELSE IS NEW!? NAM IS HEAVILY SHADOWED
ALONG THE SIERRA FRONT, WHILE GFS SPILLS PRECIP RIGHT OVER IN THE
UNSTABLE ENVIRONMENT. LEANING TOWARD THE GFS - THIS WILL LEAD TO
CONVECTIVE HEAVY SNOW SHOWERS OUTSIDE THE SIERRA AND WE WILL SEE
SIGNIFICANT VARIATIONS IN SNOW AMOUNTS OVER SHORT DISTANCES. AN
IMPORTANT POINT TO COMMUNICATE. NAM HAS SIGNALS OF EAST-WEST
BANDING WELL NORTH OF RENO, WHILE GFS HAS THE BAND EARLIER AND
CLOSER TO RENO/I-80 PLUS A SECONDARY BAND THURS EVE NEAR WMC/LOL.
IF THESE BANDING FEATURES FORM, SNOW AMOUNTS COULD EASILY DOUBLE
FOR LOCATIONS IMPACTED GIVEN HIGH SNOW RATIOS.
LAKE EFFECT - FORECAST SOUNDINGS AT RNO/CXP FOR THURSDAY SHOW
A VERY UNSTABLE AIRMASS, -13C AT 700MB, AND NOT OVERLY STRONG
WESTERLY FLOW. THIS WOULD TEND TO FAVOR LAKE EFFECT SNOW BANDS
DEVELOPING OFF OF TAHOE. WATER TEMPERATURE HAS COOLED OFF TO 45F
BUT WARM ENOUGH TO BEEF UP THE INSTABILITY. SO WE'VE INCREASED
SNOW POTENTIALS FOR CARSON CITY AND CARSON VALLEY, PERHAPS 3-6
INCHES OR MORE IF THIS BAND INDEED DOES FORM.
IMPACTS - WE'VE BEEN SAYING THIS FOR DAYS BUT IT'S HIGHLY
RECOMMENDED IF PEOPLE HAVE FLEXIBILITY IN TRAVEL PLANS FOR THE
HOLIDAY, GO TODAY/THIS EVENING OR WAIT UNTIL CHRISTMAS MORNING.
TOMORROW WE'LL SEE MANY OF THE HIGHWAYS IMPACTED BY SNOWFALL AND
BLOWING SNOW. IN THE SIERRA - WITH STRONG WINDS SOME LOCAL
BLIZZARD CONDITIONS ARE LIKELY OVER THE PASSES.
COLD - TEMPERATURES FRIDAY INTO SATURDAY WILL BE COLD AND WITH
ANTICIPATED SNOW COVER WILL GET QUITE COLD FRIDAY NIGHT. IF SKIES
CLEAR FRIDAY NIGHT, WORST CASE SCENARIO IS WE COULD SEE LOWS NEAR
OR JUST BELOW ZERO IN WESTERN NEVADA VALLEYS WITH -10F IN THE
SIERRA VALLEYS. FOR ALL THOSE GOING SKIING CHRISTMAS DAY, IT GOES
WITHOUT SAYING TO DRESS FOR COLD AND WIND! CS
.LONG TERM...
UPPER RIDGE WILL BRING WARMING TO MOUNTAIN TOPS SAT-SAT NIGHT
WHILE VALLEYS REMAIN VERY COLD, ESPECIALLY AREAS THAT RECEIVE MORE
THAN A FEW INCHES OF SNOW CHRISTMAS EVE. IN FACT, THE FLOW INTO
THE WEST COAST IS GOING TO BE MUCH WEAKER FOR THE FIRST HALF OF
NEXT WEEK WITH ONLY A COUPLE OF WEAK SHORTWAVES WORKING THROUGH
THE REGION. SO VALLEY INVERSIONS ARE GOING TO REMAIN STRONG FOR
MUCH OF THE PERIOD WITH THE ONLY CHANCE OF BRIEF MIXOUT BEING
MONDAY AS FIRST SHORTWAVE FEATURE PASSES. OVERNIGHT LOWS WILL BE
COLDEST SUNDAY MORNING WITH MANY LOCATIONS DROPPING TO SINGLE
DIGITS ABOVE AND BELOW ZERO. TEMPERATURES WILL BE SLOW TO WARM
EARLY NEXT WEEK.
FIRST SHORTWAVE WILL APPROACH LATE SUNDAY AND MOVE ACROSS THE AREA
SUNDAY NIGHT INTO EARLY MONDAY. THE FLOW BEGINS TO SPLIT AS THIS
SHORTWAVE MOVES INLAND AND PRECIPITATION POTENTIAL IS GOING TO BE
GREATLY LIMITED. WE MAINTAINED A LOW END CHANCE FOR THE SIERRA
WITH SLIGHT CHANCES IN THE VALLEYS. CONFIDENCE IS LOW IN HOW MUCH
SNOW MAY FALL IN THE SIERRA, BUT RIGHT NOW MODELS ARE LEANING ON
JUST A FEW INCHES. STILL, THERE COULD BE IMPACTS FOR ROADWAYS
ACROSS THE NORTHERN SIERRA FOR THE MONDAY MORNING COMMUTE
FOLLOWING THE HOLIDAY WEEKEND. SO IT IS WORTH WATCHING. ANOTHER
WEAKER SHORTWAVE IS POSSIBLE TUE-TUE NIGHT, DROPPING IN RIGHT
BEHIND THE FIRST ONE. HOWEVER, CONFIDENCE IS LOW FOR THIS SECOND
SYSTEM (THE GFS DOES NOT EVEN SHOW IT). HOHMANN
&&
.AVIATION...
NEXT SYSTEM IS DROPPING TOWARD THE AREA AND WILL BRING INCREASING
WINDS AND A GOOD CHANCE OF SNOW BY THURSDAY MORNING. WINDS WILL
INCREASE RATHER DRAMATICALLY ACROSS RIDGES BETWEEN 04Z-08Z WITH
GUSTS APPROACHING 100KT OVERNIGHT AND THURSDAY AHEAD OF UPPER
TROUGH. THIS WILL LIKELY RESULT IN AN INCREASE IN TURBULENCE AND
LLWS AFTER MIDNIGHT WITH CONDITIONS NOT IMPROVING UNTIL MID-LATE
AFTERNOON FOR THE NORTHERN SIERRA/SIERRA FRONT/BASIN-RANGE AND
NOT UNTIL LATER IN THE EVENING FARTHER SOUTH ACROSS MONO/MINERAL
COUNTIES. SURFACE GUSTS WILL BE 25-40KT AHEAD OF THE PRECIPITATION
BEGINNING IN THE TAHOE BASIN BEFORE DAYBREAK THURSDAY AND
SPREADING TO LOWER ELEVATIONS, ESPECIALLY SOUTH OF I-80 EARLY IN
THE MORNING.
SNOW POTENTIAL IS HIGH WITH THIS SYSTEM WITH A STEADY AND POWDERY
TYPE SNOW FOR THE TAHOE BASIN AIRPORTS. MT/TRRN OBSCUREMENT IS
LIKELY WITH AIRPORT CLOSURE DUE TO POOR VISIBILITY AND
ACCUMULATING SNOW LIKELY FOR AT LEAST 6-8 HOURS THURSDAY.
FOR KMMH AND LOWER ELEVATION AIRPORTS, SNOWFALL IS GOING TO BE
MORE SHOWERY IN NATURE WITH MORE VARIABLE CIGS/VSBYS, STARTING
MOSTLY AFTER DAYBREAK AND PERSISTING MUCH OF THE DAY. HEAVIER
SNOW BANDS ARE POSSIBLE FOR KRNO/KCXP WHERE ACCUMULATIONS ARE
GOING TO BE QUITE VARIABLE RANGING FROM AN INCH TO 4+ INCHES. AIR
TEMPERATURES WILL BE CLOSE TO 30 DEGREES DURING HEAVIER SNOW BANDS
WHICH WILL PROMOTE QUICK ACCUMULATIONS. THE DEGREE OF IMPACT WILL
DEPEND HEAVILY ON WHERE THESE BANDS SET UP WITH A SLIGHTLY HIGHER
CONFIDENCE AT KCXP WHERE LAKE EFFECT OFF TAHOE IS POSSIBLE.
HOHMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING FROM 1 AM TO 10 PM PST THURSDAY NVZ002.
WINTER WEATHER ADVISORY FROM 1 AM TO 10 PM PST THURSDAY NVZ005.
WINTER WEATHER ADVISORY FROM 7 AM TO 10 PM PST THURSDAY
NVZ001-003-004.
CA...WINTER STORM WARNING FROM 1 AM TO 10 PM PST THURSDAY CAZ071-072.
WINTER WEATHER ADVISORY FROM 1 AM TO 10 PM PST THURSDAY CAZ070.
WINTER STORM WARNING FROM 10 AM THURSDAY TO 4 AM PST FRIDAY
CAZ073.
&&
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)The national radar mosaic for the moment the first event began.
3 heavy snow. Local standard time, as filed.
Five inches of snow fell in Cedarville between late evening on the 23rd and the morning of the 24th.
An estimated 8 to 10 inches of snow fell southwest of Susanville in the higher elevations per SNOTEL and HADS sensors. In the lower elevations, 5 inches of snow was noted at the Portola CO-OP station.
Eighteen to 24 inches of snow fell at ski areas and along and west of highway 89 on the 24th. Elsewhere, a widespread 10 to 14 inches of snow fell around Lake Tahoe, in Truckee, and east to the foothills of the Verdi Range.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2015Every state in 2015This day in weather historyWarnings in California, December 2015
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: 615379, 615378, 615380.