Storm Summary Number 7 for West Coast Multi-Hazard Atmospheric
River Events
NWS Weather Prediction Center College Park MD
700 AM PST Sun Jan 07 2023

...Heavy rain, snow, and high winds continue across northern and
central CA...

Winter Storm Warnings are in effect for portions of the Sierra
Nevada and Klamath Mountain Ranges.

High Wind Warnings are in effect for northern California and
south-central Oregon.

Flood Watches are in effect for much of coastal California, and
the southern Sacramento Valley through San Joaquin Valley.

Wind Advisories are in effect over Coastal California, and over
the Sacramento Valley through the San Joaquin Valley.

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

At 600 AM PST...Latest surface observations and RADAR depicted a
stream of moderate to locally heavy rainfall focusing over
northern and central California associated with the atmospheric
river that arrived Friday evening, with moderate snowfall noted
over the higher elevations of the Klamath and Sierra Nevada
ranges. A secondary push of moisture was depicted moving towards
the northern California coast ahead of another storm system moving
eastward. Further north, scattered light to moderate rainfall was
occuring over coastal Washington.

...Selected preliminary Storm Total Snowfall in inches from 700 AM
PST Wed Jan 04 through 600 AM PST Sun Jan 08...

...CALIFORNIA...
KIRKWOOD MEADOWS 1 SSE               33.0                    
PINECREST 2 E                        32.0                    
TWIN BRIDGES 2 ESE                   26.0                    
DONNER PEAK 1 W                      22.0                    
SOUTH LAKE 1 NNE                     22.0                    
JUNE MOUNTAIN SKI BASE               18.0                    
LONE PINE 11 SW                      17.0                    
MAMMOTH MOUNTAIN SKI BASE            16.0                    
HEAVENLY SKI BASE                    12.0                    
HETCH HETCHY 10 NE                   12.0                    

...NEVADA...
MT CHARLESTON                        12.0                    
MT ROSE SKI BASE                     12.0                    

...WASHINGTON...
LEAVENWORTH 1 NNE                     7.0                    
TWISP 3 SE                            5.3                    
MAZAMA 6 ESE                          4.0                    

...Selected preliminary Storm Total Rainfall in inches from 700 AM
PST Wed Jan 04 through 600 AM PST Sun Jan 08...

...CALIFORNIA...
HEARST CASTLE 14.2 NW                8.37                    
GONZALES 15.5 SW                     7.04                    
OLD MAN MOUNTAIN                     6.57
UKIAH MUNICIPAL APT                  6.15                    
HONEYDEW                             6.08                    
SIMS                                 5.85                    
FRENCH GULCH                         5.60                    
THREE PEAKS                          5.59                    
MANCHESTER                           5.45                    
LOS GATOS                            4.17                         
              
MORAGA 2.4 NNW                       3.82                    
BURLINGAME 2.0 WSW                   3.71                    
THOUSAND OAKS 2.1 WSW                2.91
SACRAMENTO INTL APT                  2.98
SAN FRANCISCO INTL APT               2.72                      
K6BPM SANTA BARBARA                  2.39                    
ATASCADERO 2.3 NE                    2.31                         
                              
LOS ANGELES INTL APT                 1.78                    

...OREGON...
QUAIL PRAIRE LOOKOUT                 2.88                    
LEBANON                              2.74                    
CANNIBAL MOUNTAIN                    2.57                    
CEDAR                                2.25                    

...WASHINGTON...
JEFFERSON CREEK                      5.59                    
OWL MOUNTAIN                         3.08                    
MOUNT CRAG                           3.00                    
HUCKLEBERRY RIDGE                    2.11                    
MT. BAKER - HEATHER MEADOWS          1.97                    

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

...CALIFORNIA...
KIRKWOOD MEADOWS 1.2 S                119                    
GRAPEVINE 3 SSE                       104                    
PULGA 2 NNW                           102                    
PABLO POINT                           101                    
YORKVILLE 5.5 NW                       95                    
CAPETOWN 6 ENE                         94                    
COBB RIDGE WEST                        91                    
ROAD TO RANCHES                        90                    
HIGH GLADE LOOKOUT                     89                    
FERNDALE 6.4 S                         88                    
MAGIC MOUNTAIN TRUCK TRL               87                    
AMERICAN HOUSE 6 NW                    84                    
AGUA DULCE 8 S                         81                    
BIG BEAR CITY 13 ESE                   72                    
MOUNTAIN GATE 3 NNE                    72                    
CRESCENT CITY 1 ESE                    69                    
JULIAN 9 S                             65                    
BLACK MOUNTAIN 7 E                     64                    


The deluge of heavy rain, snow, and strong winds with this
atmospheric river will wind down today over northern and central
California, although widespread rainfall of 1-2"+ are expected
over northern and central California through Sunday. Very little
reprieve will occur from the parade of atmospheric rivers as a
more intense atmospheric river is forecast to arrive over coastal
California tomorrow morning, reloading the heavy rain, snow, and
high winds through midweek.  The cumulative effect of additional
rainfall will lead to considerable flood impacts across much of
central and northern California, including rapid water rises, rock
slides and mudslides. Isolated major river flooding is expected
through the weekend into next week, with record river levels
possible. Numerous instances of flash flooding and debris flows
are possible over burn scar areas. Furthermore, additional
snowfall totals measured in feet will fall atop the Klamath and
Sierra Nevada Ranges through midweek, which will lead to dangerous
(at times impossible) travel conditions, especially over 4000
feet.

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

Asherman/Russell