A series of storms fueled by a tropical moisture tap pounded the Mojave Desert and southern Great Basin for several days. Extremely heavy snow and widespread flooding resulted.
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 VEF wrote it up.
A series of storms fueled by a tropical moisture tap pounded the Mojave Desert and southern Great Basin for several days. Extremely heavy snow and widespread flooding resulted.
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 Las Vegas, NV wrote its last area forecast discussion before the first event at Dec 17, 9:26 AM PST, 3 hours 34 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
926 AM PST FRI DEC 17 2010
.SYNOPSIS...A PERSISTENT AND RELATIVELY WARM SOUTHWEST FLOW WILL
BRING ABUNDANT PACIFIC MOISTURE ACROSS THE AREA TODAY THROUGH EARLY
NEXT WEEK. HEAVY SNOW WILL DEVELOP IN THE HIGHER ELEVATIONS OF THE
SIERRA TODAY AND WILL CONTINUE THROUGH AT LEAST SUNDAY. MEANWHILE
VALLEY RAIN AND HIGH ELEVATION SNOW WILL SPREAD ACROSS THE AREA AND
WILL CONTINUE OFF AND ON THROUGH THE WEEKEND. TEMPERATURES WILL BE
BE CLOSE TO NORMAL AND SNOW LEVELS WILL GENERALLY CLIMB ABOVE 8000
FEET BY SATURDAY.
&&
.UPDATE...LIGHT RAIN/SNOW SPREAD EAST A BIT FASTER THAN PREVIOUSLY
FORECAST. UPDATED TO REFLECT THIS TREND AND ALSO TO LOWER MAX TEMPS
IN MANY AREAS WHICH WILL BE HELD DOWN BY THE EARLIER ARRIVAL OF
PRECIPITATION AND THICK CLOUD COVER. IT STILL LOOKS LIKE SNOWFALL
EAST OF THE SIERRA TODAY SHOULD REMAIN BELOW ADVISORY CRITERIA THEN
SNOW LEVELS RISE QUITE A BIT WHEN THE MORE ABUNDANT MOISTURE MOVES
IN. SO...WARNINGS OR ADVISORIES OUTSIDE OF THE SIERRA ARE NOT LIKELY
AT THIS TIME. -HARRISON-
&&
.AVIATION...FOR MCCARRAN...THIS MORNING WILL SEE THE FIRST OF
SEVERAL RAIN BANDS MOVE THROUGH THE VALLEY. WITH EACH BAND THE
CEILINGS HAVE THE POTENTIAL TO DROP TO THE 3500-5000 FOOT RANGE.
THIS PATTERN SHOULD LAST THROUGH THE DAY. THIS EVENING RAIN WILL
BECOME MORE CONTINUOUS AND CEILINGS WILL DROP AND STAY DOWN.
DIFFICULT TO SAY HOW LOW AS THIS PATTERN IS NOT A COMMON EVENT. FOR
NOW WILL FORECAST THEM DOWN TO 3000 FEET...BUT THIS MAY BE TOO HIGH.
WILL REFINE IN LATER TAFS/AMENDMENTS. WINDS WILL BE LIGHT THE NEXT
24 HOURS FROM THE SOUTH TO SOUTHWEST.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...LOWER CIGS AND PRECIPITATION WILL MOVE ACROSS MUCH OF
THE REGION TODAY. CEILINGS WILL DROP BELOW 1000 FT IN MANY AREA OF
CENTRAL NEVADA AND INYO COUNTY THROUGH SATURDAY MORNING. THE SIERRA
WILL STAY OBSCURED WITH STRONG WINDS AND HEAVY SNOW. SOUTHERN
NEVADA...WESTERN ARIZONA AND SOUTHEAST CALIFORNIA WILL SEE WIDE
SPREAD RAIN AND CIGS BELOW 3000 FEET ALONG WITH MOUNTAIN
OBSCURATIONS. THESE CONDITIONS WILL LIKELY CONTINUE THROUGH SUNDAY.
-JACQUES-
&&
.PREV DISCUSSION...
409 AM PST FRI DEC 17 2010
.SHORT TERM...TODAY THROUGH SUNDAY...A LARGE STATIONARY LOW NEAR THE
GULF OF ALASKA WAS DIRECTING THE LONG EXPECTED PACIFIC MOISTURE
PLUME INTO THE WEST COAST THIS MORNING. RADAR RETURNS SHOWED
EXTENSIVE PRECIPITATION ACROSS CENTRAL CALIFORNIA AND SOME LIGHT
RETURNS WERE ALREADY MOVING INTO NORTHWEST SAN BERNARDINO COUNTY.
WHILE IT IS STILL APPARENT THAT THE SOUTHERN SIERRA WILL INTERCEPT A
GREAT DEAL OF PRECIPITATION...IT IS DIFFICULT TO DETERMINE PRECIP
AMOUNTS FOR THE REST OF THE AREA TODAY AND TONIGHT AS THE MOIST FLOW
IS ACCOMPANIED BY A SHORTWAVE RIDGE MIGRATING OVERHEAD. THERE ARE
CONSIDERABLE DIFFERENCES BETWEEN THE NAM...GFS AND SREF QPF
DEPICTIONS TODAY AND TONIGHT WITH THE NAM BEING ON THE GENEROUS SIDE
AND THE GFS MORE LIMITED. THE CONCERN IS THAT SNOW LEVELS WILL BE
LOW ENOUGH INITIALLY TODAY AND TONIGHT FOR THE WHITE
MOUNTAINS...CENTRAL NYE/LINCOLN COUNTIES AND THE SPRING MOUNTAINS
FOR SNOW TO IMPACT TRAVEL IF MORE THAN A FEW INCHES FALLS. SINCE
THIS MOIST WARM AIR ADVECTION PATTERN IS FAIRLY RARE FOR THE
FORECAST AREA...IT IS A BIT OF A TOUGH CALL. FOR NOW...WILL KEEP
SNOW AMOUNTS GENERALLY IN THE 1-3 INCH RANGE FOR AREAS DOWNSTREAM
FROM THE SOUTHERN SIERRA BUT WILL MONITOR CLOSELY. IN ANY CASE...THE
LATEST MODEL SOLUTIONS INDICATE THE BEST POTENTIAL FOR PRECIP LATER
TODAY AND TONIGHT ACROSS SOUTHERN NEVADA SO THIS WILL PROVIDE A
LITTLE TIME TO SEE HOW PRECIP DEVELOPS IN THIS PATTERN. A LITTLE
BREAK IN THE MOISTURE IS FORECAST SATURDAY FOR DECREASING POP
VALUES. MORE OF A CYCLONIC FLOW IS THEN FORECAST TO DEVELOP OVER THE
EASTERN PACIFIC BY SUNDAY AND CONCENTRATED DEEP MOISTURE TAKES
BETTER AIM ON SOUTHERN CALIFORNIA AND SOUTHERN NEVADA. SNOW LEVELS
WILL RISE AND SIGNIFICANT SNOW IMPACTS WILL BE CONFINED TO AREAS
ABOVE 9000 FEET. THIS SETUP HAS THE POTENTIAL TO PRODUCE SOME
SIGNIFICANT RAINFALL OVER THE MOJAVE DESERT.
.LONG TERM...MONDAY THROUGH THURSDAY...UPPER LOW IN THE EASTERN
PACIFIC WILL ALLOW FOR A SIGNIFICANT MOISTURE PLUME TO AFFECT THE
WESTERN STATES FOR MUCH OF THE EXTENDED PERIOD. THERE WILL BE
VARIOUS SHORTWAVES EMBEDDED IN THE FLOW AND IT LOOKS LIKE MUCH OF
THE REGION WILL SEE PRECIPITATION NEARLY CONTINUOUSLY THROUGH THE
EXTENDED PERIOD. THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THIS
SYSTEM AND THE MAIN CONCERNS ARE MAINLY IN THE AMOUNTS OF
PRECIPITATION. THE SIERRA STILL LOOKS TO BE THE MAJOR WINNER WITH A
SIGNIFICANT AMOUNT OF SNOW AT THE HIGHER ELEVATIONS AND GENERALLY
LOWER PRECIPITATION AMOUNTS EAST DUE TO RAINSHADOWING. HOWEVER...A
SHORTWAVE EXPECTED TO ARRIVE WEDNESDAY IS TAKING A MORE SOUTHERLY
TRACK WHICH WILL TURN THE FLOW SOUTH TO SOUTHWEST WHICH SHOULD
REALLY REDUCE THE RAINSHADOW EFFECT. THIS COULD BE THE WETTEST DAY
FOR SOUTHERN CWA VALLEYS. DID RAISE POPS FOR NEARLY THE ENTIRE CWA
AND IF THE MODELS REMAIN CONSISTENT...THEY SHOULD CONTINUE TO
INCREASE. THIS SYSTEM IS NOT PARTICULARLY COLD AND TEMPERATURES WILL
REMAIN AT TO SLIGHTLY ABOVE NORMAL.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...WINTER STORM WARNING FROM 4 AM FRIDAY TO 4 PM PST SUNDAY FOR
CAZ519.
&&
ADAIR/GORELOW
HTTP://WEATHER.GOV/LASVEGASHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LAS VEGAS NV 541 AM PST FRI DEC 17 2010 CAZ519-180800- EASTERN SIERRA SLOPES- 541 AM PST FRI DEC 17 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST CALIFORNIA. .DAY ONE...TODAY AND TONIGHT SNOWFALL WILL BECOME HEAVIER LATER TODAY AND TONIGHT ABOVE 7000 FEET WITH 6 TO 12 INCHES OF NEW SNOW LIKELY OVER THE NEXT 24 HOURS. A WINTER STORM WARNING IS IN EFFECT THROUGH SUNDAY. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY HEAVY SNOW WILL CONTINUE SATURDAY AND SUNDAY WHILE SNOW LEVELS RISE TO BETWEEN 7500 AND 8000 FEET. STRONG WINDS WILL ACCOMPANY THE SNOW OVER THE RIDGE TOPS WITH GUSTS OVER 60 MPH. A TOTAL OF 1 TO 2 FEET OF SNOW CAN BE EXPECTED NEAR 8000 FEET WITH 3 TO 6 FEET TOWARD THE CREST. PERIODS OF HEAVY SNOW MAY PERSIST OVER THE SOUTHERN SIERRA THROUGH THURSDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. HOWEVER... SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. AZZ001>003-036-CAZ520>527-NVZ014>022-180800- NORTHWEST PLATEAU-LOWER COLORADO RIVER VALLEY-NORTHWEST DESERTS- LAKE MEAD NATIONAL RECREATION AREA-OWENS VALLEY- WHITE MOUNTAINS OF INYO COUNTY-DEATH VALLEY NATIONAL PARK- WESTERN MOJAVE DESERT-EASTERN MOJAVE DESERT-MORONGO BASIN- CADIZ BASIN-SAN BERNARDINO COUNTY-UPPER COLORADO RIVER VALLEY- ESMERALDA AND CENTRAL NYE COUNTY-LINCOLN COUNTY- NORTHEAST CLARK COUNTY-WESTERN CLARK AND SOUTHERN NYE COUNTY- SHEEP RANGE-SPRING MOUNTAINS-LAS VEGAS VALLEY- SOUTHERN CLARK COUNTY- 541 AM PST FRI DEC 17 2010 /641 AM MST FRI DEC 17 2010/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST ARIZONA...SOUTHEAST CALIFORNIA AND SOUTHERN NEVADA. .DAY ONE...TODAY AND TONIGHT AREAS OF LIGHT RAIN AND SNOW WILL OCCUR ACROSS THE REGION TODAY AND TONIGHT. MEASURABLE SNOWFALL WILL BE CONFINED TO ELEVATIONS ABOVE 6000 FEET WITH ACCUMULATIONS GENERALLY OF 1 TO 3 INCHES. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY SNOW LEVELS WILL CLIMB ABOVE 8000 FEET ACROSS MUCH OF THE REGION SATURDAY AND REMAIN HIGH THROUGH THE MIDDLE OF THE WEEK. SIGNIFICANT SNOW ACCUMULATIONS COULD OCCUR IN THE HIGH MOUNTAINS OF SOUTHERN NEVADA SUNDAY AND MONDAY. WHILE SOME AREAS WITHIN THE MOJAVE DESERT MAY SEE SUBSTANTIAL RAINFALL AMOUNTS DURING THE PERIOD SUNDAY THROUGH WEDNESDAY...ANY RUNOFF IMPACTS SHOULD BE MINIMIZED BY STEADY LIGHT TO MODERATE RAINFALL RATES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. HOWEVER...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. JA
The national radar mosaic for the moment the first event began.
13 flash flood, 2 heavy snow, 1 heavy rain, 1 flood. Local standard time, as filed.
A spotter measured a total of 88.1 inches of snow in Aspendell (8500'). A CoCoRAHS observer measured 25.8 inches 8.5 miles west of Bishop (6000').
Caltrans reported two feet of snow on Highway 168 at Westgard Pass (7300').
Flash flooding washed boulders onto Whitney Portal Road.
Heavy rain produced minor flooding of numerous streets and several yards in Bishop.
At least a foot of water flowed across Highway 395 south of Olancha. The ending time is estimated.
Several county roads in Death Valley National Park were covered by water and debris.
Flash flooding at the intersection of Irwin Road and Copper City Road trapped two men in their vehicle.
The intersection of Cedar Road and Jasper Road was flooded, with a vehicle possibly stuck in the water.
A vehicle was stuck in flood waters on Kennedy Meadow Road just east of Highway 395.
Many roads on Fort Irwin were flooded and/or washed out.
Yucca Mesa Road and Indio Avenue were closed due to softball sized rocks and a foot of water on the roads.
Eight to ten inches of water flowed through the intersection of Cedar Road and Jasper Road.
The Mojave River overflowed its banks due to a combination of heavy rain and emergency release of water from Cedar Spring Dam near Arrowhead. Numerous roads were covered with mud and closed, one bridge was washed out, a broken levee flooded a neighborhood, and three swift water rescues were performed.
Several roads were closed by flooding in Yucca Valley and Joshua Tree. One vehicle was stuck in the water on Mojave Ranch Road in Joshua Tree.
A car was stuck in floodwaters on Old Woman Springs Road at Pipes Canyon Road. Reche Road in Landers was also full of debris.
Highway 178 flooded just north of Trona, trapping seven people in vehicles.
The community of Tecopa was completely cut off when the only three paved roads into and out of the town were flooded. More than 18 inches of water flowed across one road for two days straight.
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: 271411, 271425, 271468, 271413, 271474, 272889, 272878, 272891, 272894, 272895, 272897, 272900, 272919, 272923, 272924, 272925, 272926.