Storm Summary Number 4 for Significant California Atmospheric River
NWS Weather Prediction Center College Park MD
700 PM PST Tue Jan 10 2023

...Atmospheric River event coming to an end across California as
storm system weakens and pushes inland...

Winter Storm Warnings are in effect for the Sierra Nevada Range,
northern Wasatch Mountains, and southern Wyoming.

High Wind Warnings are in effect for the Transverse Mountains.

Flood Watches extend along much of California's Central 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 southern 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
light to localized moderate rainfall across central and northern
California, south of the weakening low-pressure system, as a
result of continued onshore flow. Southern California, where the
heaviest rainfall totals of the Atmospheric River event were
located, had also begun to clear out, as the bulk of the
precipitation associated with the storm system was located just
east of the eastward progressing cold front in northwestern
Arizona, Utah, and southern Idaho.

...Selected preliminary Storm Total Snowfall in inches from 500 PM
PST Sun Jan 08 through 600 PM PST Tue Jan 11...

...CALIFORNIA...
MAMMOTH MOUNTAIN SKI BASE            54.0                    
LONE PINE 11 SW                      47.0                    
SOUTH LAKE 1 NNE                     41.0                    
ROUND VALLEY 9 WNW                   32.0                    
SUSANVILLE 5 WNW                     15.0                    
SODA SPRINGS 2 ENE                   14.0                    
WILLOW CREEK 4 WSW                   14.0                    
BEAR VALLEY 2 N                      12.0                    
DEEP SPRINGS 11 WSW                  12.0                    

...NEVADA...
MT. ROSE SKI BASE                    47.0                    
INCLINE VILLAGE 1 NNW                12.0                    

...Selected preliminary Storm Total Rainfall in inches from 500 PM
PST Sun Jan 08 through 600 PM PST Tue Jan 11...

...CALIFORNIA...
VENTURA                             18.78                    
NORDHOFF RIDGE                      18.31                    
MATILIJA DAM                        17.17                    
SAN MARCOS PASS                     17.17                    
WHITE LEDGE PEAK                    16.85                    
ALISAL RESERVOIR                    13.81                    
ROCKY BUTTE                         12.91                    
THREE PEAKS (SANTA LUCIA)           12.75                    
DOULTON TUNNEL                      12.56                    
HOPPER CANYON                       10.79                    
NATURE POINT NEAR BASS LAKE          9.60                    
MONTECITO                            8.85                    
CHALK PEAK                           8.58                    
MINING RIDGE                         8.40                    
DINKEY                               7.20                    
SAN FRANCISCO INTL AIRPORT           1.90                    
SANTA MONICA                         1.71                    
LOS ANGELES INTL AIRPORT             1.70                    
SACRAMENTO INTL AIRPORT              1.49                    

...NEVADA...
MID VALLEY                           3.52                    
KYLE CANYON                          3.34                    
GENOA                                1.95                    
KINGS CANYON                         1.84                    
GLENBROOK                            1.26                    

...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                    
JOAQUIN RANGE                          78                    
KNEELAND 6 SSE                         77                    
SILVERWOOD LAKE                        76                    
SANDSTONE PEAK                         71                    
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                    


Conditions across California continue to improve as the latest
Atmospheric River event winds down, with light to moderate
precipitation expected to persist through the overnight hours
before the next system arrives early Thursday morning. Tomorrow,
moisture will stream ahead of a large cyclone in the eastern
Pacific Ocean, which will produce heavy precipitation in northern
California. As the system slowly approaches the West Coast,
precipitation will spread north into the Pacific Northwest
Wednesday night and continue through the end of the work week. 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, especially over burn scar areas. Soils in California are
saturated from above average rainfall over the past few weeks,
which means it won't take much additional rainfall to trigger
flooding.

This will be the last Storm Summary issued by the Weather
Prediction Center for this event. Please refer to your local
National Weather service office for additional information.

Russell