Storm Summary Number 2 for Significant California Atmospheric River
NWS Weather Prediction Center College Park MD
700 PM PST Mon Jan 09 2023

...Significant heavy rainfall, mountain snow, and strong winds
will continue to impact CA and western NV into Tuesday...

Winter Storm Warnings are in effect over the Sierra Nevada and
Klamath Ranges.

High Wind Warnings extend along much of coastal California, and
over portions of the Sacramento Valley.

Flood Watches extend along much of coastal California, into the
Sacramento Valley.

Winter Weather Advisories are in effect for northern California,
central Nevada, the Wasatch Mountains, and much of the central and
northern Rockies.

Wind Advisories are in effect across much of California, southern
Nevada, and western portions of Utah and Arizona.

For a detailed graphical depiction of the latest watches, warnings
and advisories, please see www.weather.gov

At 600 PM PST...Current RADAR and surface observations detected
widespread moderate to heavy rainfall over much of central and
southern California, associated with an intense atmospheric river
plume surging inland ahead of a cold front situated along the
coastline just south of San Francisco. The heaviest axis of
precipitation was located north of Los Angeles in the southern
portion of the San Joaquin Valley. Snow was confined to the higher
elevations of the central and southern Sierra Nevada Range, with
the heaviest snowfall rates limited to elevations above 7500'.
Strong wind gusts were also ongoing across much of southern
California, especially in the higher elevations of the Transverse
and Sierra Nevada Ranges.

...Selected preliminary Storm Total Snowfall in inches from 500 PM
PST Sun Jan 08 through 600 PM PST Mon Jan 09...

...CALIFORNIA...
MAMMOTH MOUNTAIN SKI BASE            18.0                    
SUSANVILLE 5 WNW                     15.0                    
SODA SPRINGS 2 ENE                   14.0                    
WILLOW CREEK 4 WSW                   14.0                    
BEAR VALLEY 2 N                      12.0                    

...Selected preliminary Storm Total Rainfall in inches from 500 PM
PST Sun Jan 08 through 600 PM PST Mon Jan 09...

...CALIFORNIA...
SAN MARCOS PASS                     13.37                    
NORDHOFF RIDGE                      12.32                    
ROCKY BUTTE                         11.54                    
ALISAL RESERVOIR                    11.10                    
THREE PEAKS (SANTA LUCIA)           10.71                    
BONNY DOON FIRE STATION ON MARTI    10.54                    
DOULTON TUNNEL                       9.92                    
HOPPER CANYON                        8.90                    
MONTECITO                            8.85                    
NATURE POINT NEAR BASS LAKE          8.36                    
CHALK PEAK                           7.91                    
MINING RIDGE                         7.41                    
DINKEY                               7.20                    
SAN FRANCISCO INTL AIRPORT           1.61                    
SANTA MONICA                         1.25                    

...Selected preliminary Peak Wind gusts in miles per hour earlier
in the event...

...CALIFORNIA...
COPPER CANYON                          98                    
WASHOE CITY 2 NNE                      98                    
AGUA DULCE 8 S                         88                    
WEITCHPEC 11 WSW                       86                    
HIGH GLADE LOOKOUT                     80                    
KNEELAND 6 SSE                         77                    
CAYUCOS 7 N                            69                    
CRESCENT CITY 3 NW                     68                    

...OREGON...
YACHATS 2 SE                           86                    
GARIBALDI 2 WNW                        83                    
PILOT ROCK 9 S                         75                    

...WASHINGTON...
FRANCES 6 ESE                          68                    
RYDERWOOD 2 SW                         58                    
TOKELAND 1 ESE                         57                    


The barrage of heavy rainfall, mountain snow, and strong winds
will persist through tonight across central and southern
California as the Atmospheric River slowly shifts southward, while
areas further north experience a brief reprieve from the impacts
before the next surge of moisture moves onshore early Tuesday
morning. The cumulative effect of successive heavy rain events
will lead to additional considerable flood impacts, including
rapid water rises and mudslides across California, and portions of
far western Nevada. Numerous instances of flash flooding and
debris flows are possible over burn scar areas, and scattered
power outages are also likely due to the strong wind gusts. Atop
the Sierra Nevada peaks, snowfall totals of 1-4 feet through
Tuesday will lead to dangerous travel above 4000 feet. Mountain
communities will be at increasing risk of infrastructure impacts
and avalanches as snow load continues to increase.

The next Storm Summary will be issued by the Weather Prediction
Center at 700 AM PST. Please refer to your local National Weather
Service office for additional information on this event.

Russell/Asherman