Storm Summary Number 2 for West Coast to Upper Midwest Storm System
NWS Weather Prediction Center College Park MD
700 PM PST Sat Dec 31 2022

...Persistent onshore flow and anomalous moisture continue to
produce moderate to heavy rain at low elevations and snow at high
elevations in central California...

Winter Weather Advisories and Winter Storm Warnings are in effect
from the Sierra Nevada through much of Nevada, Utah, and Wyoming
and for parts of southern Idaho, western Colorado, northwestern
Nebraska, and the higher elevations of Arizona and New Mexico.

Winter Storm Watches are in effect for northeastern Colorado
through central and northeastern Nebraska, southern and central
South Dakota, northwestern Iowa, southern and central Minnesota,
and northwestern Wisconsin.

Flash Flood and Flood Watches are in effect for much of central
California, coastal southern California, inland northern
California, and northwestern Nevada.

High Wind Warnings are in effect for California's Transverse
Ranges, part of southeastern Wyoming, and southwestern New Mexico.

Wind Advisories are in effect for southern California and Nevada
and parts of northwestern and southeastern Arizona.

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

At 600 PM PST...A frontal system was analyzed over central
California with a cold front extending to the southwest and a
stationary front extending to the east. This system is focusing
persistent onshore flow and anomalous moisture over the state of
California, resulting in moderate to heavy rainfall and flash
flooding at low and middle elevations and snow at high elevations
from Sacramento to Los Angeles and eastwards. In addition to
precipitation, impressive wind gusts have been reported across
California and extreme western Nevada as a result of the tight
pressure gradient across the region.

...Selected preliminary Storm Total Rainfall in inches from 400 AM
PST Sat Dec 30 through 600 PM PST Sun Dec 31...

...CALIFORNIA...
HOMEWOOD                             8.67                    
WHITETHORN 2.4 WSW                   8.56                    
CAMINO 1.2 N                         8.52                    
FRESH POND                           8.40                    
VOLCANO 3.2 N                        8.05                    
SANTA CRUZ 8.9 NW                    7.74                    
PLACERVILLE 0.9 NE                   7.52                    
BLUE CANYON NYACK AIRPORT            7.37                    
WHITETHORN 1.7 NNW                   6.98                    
HELL HOLE                            6.49                    
BALD MTN LOC                         6.33                    
LAYTONVILLE 9.8 NNW                  6.18                    
AVERY                                5.82                    
SOUTH LAKE TAHOE 4.9 SW              5.68                    
MOUNT ZION                           5.45                    
SOUTH FORK EEL RIVER AT LEGGETT      5.44                    
STRAWBERRY VALLEY                    5.42                    
WHITE CLOUD                          5.37                    
MOUNT ELIZABETH                      5.17                    
STEELY FORK                          4.87                    
BEN LOMOND                           4.55                    
PIEDMONT 2 N                         4.45                    
KNEELAND                             3.33                    

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

...CALIFORNIA...
PALISADES TAHOE SUMMIT                160                    
MAMMOTH MOUNTAIN                      116                    
HEAVENLY SKI SUMMIT 1 NNW              99                    
CONWAY SUMMIT                          82                    
CROWLEY LAKE 6 W                       80                    
JAWBONE                                70                    
BIRD SPRINGS PASS                      66                    
HORSE THIEF SPRINGS                    61                    
MAMMOTH YOSETIME AIRPORT               47                    

...NEVADA...
HAWTHORNE 6 NW                         93                    
YERINGTON 5 ENE                        64                    
RENO 2 NW                              55                    


Moderate to heavy precipitation will continue to fall across
California through Sunday morning with the heaviest axis of
precipitation gradually shifting south. Widespread areal average
totals of 1-2"+ are possible throughout California with localized
2-6"+ totals on Pacific-facing mountain slopes, especially along
the Sierra Nevada Range and Transverse Mountains. Snowfall will
remain confined to the high elevations (>8500 ft) with several
feet of snow possible along the southern peaks of the Sierra
Nevada Range and lesser amounts (1-2 ft) in higher elevations of
the Great Basin, Wasatch Mountains, and Tetons. The system will
push inland on Sunday and the West Coast will begin to dry out
Sunday afternoon and evening. Precipitation will spread into the
Southwest and southern and central Rockies on Sunday then into the
central and northern Plains on Monday. 

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.

Dolan/Russell