Storm Summary Number 1 for Rockies and Western U.S. Heavy Snow
NWS Weather Prediction Center College Park MD
100 PM PST Fri Dec 24 2021

...Periods of heavy snow to continue impacting the western United
States over the next several days, including lower elevations of
the Pacific Northwest...

Winter Storm Warnings and Winter Weather Advisories are in effect
across portions of the Rockies, Intermountain West, Northwest,
Sierra Nevada, and northern California.

Winter Storm Watches are in effect across parts of California and
western Oregon.

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

At 1200 PM PST...A deep upper-level trough was located over the
western U.S. along with a potent low pressure system found over
the eastern Pacific Ocean. This ares of low pressure had an
estimated central pressure of 984 mb and was found about 70 miles
west of the Washington coastline. Additionally, a separate cold
front was pushing through southern California and responsible for
a surge of moisture directed at the Southwest and central/southern
Rockies. An anomalously cold airmass remained over the Northern
High Plains and British Columbia, Canada. Radar and surface
observations indicated scattered rain and snow showers throughout
the entire western U.S., with more widespread precipitation
located across the Pacific Northwest, Sierra-Nevada, and
Southwest/Southern Rockies.

...Selected preliminary Storm Total Snowfall in inches from 400 AM
PST Wed Dec 22 through 1200 PM PST Fri Dec 24...

...ARIZONA...
ARIZONA SNOWBOWL 3 WSW               10.0                    
SUNRISE PARK                          9.0                    
FOREST LAKES 1 E                      8.0                    
FLAGSTAFF ARPT                        6.3                    

...CALIFORNIA...
MAMMOTH MOUNTAIN SKI BASE            40.0                    
NORTHSTAR SKI BASE                   26.0                    
TRUCKEE 1.6 N                        21.7                    
HOMEWOOD MOUNTAIN SKI BASE           20.0                    
SOUTH LAKE TAHOE 4.9 SW               7.0                    

...COLORADO...
MOUNT CRESTED BUTTE 4 NNW            22.5                    
COAL BANK PASS                       16.5                    
MOUNT ZIRKEL 4 SE                    16.0                    
WOLF CREEK PASS 1 SE                 14.0                    
CAMERON PASS 9 SE                    12.0                    

...IDAHO...
STANLEY                               7.9                    
BELLEVUE 0.3 SSE                      6.8                    
HAILEY                                4.0                    
BOISE CITY 6.1 SE                     2.9                    

...MONTANA...
COOKE CITY 3 N                       12.0                    
EAST PORTAL 5 NW                     11.0                    
BOZEMAN 1.5 SSE                       4.3                    

...NEVADA...
MT ROSE SKI BASE                     22.0                    
INCLINE VILLAGE 1 NNW                19.0                    
RENO 5.4 W                            4.2                    

...OREGON...
TOLLGATE                             14.0                    
KLAMATH FALLS 4 WSW                   5.5                    

...UTAH...
HERBER CITY 10.1 ESE                 11.0                    
FAIRVIEW                             10.0                    
ALTA                                  9.5                    
POWDER MOUNTAIN                       8.0                    
SPRINGDELL                            8.0                    
PARK CITY                             7.0                    

...WASHINGTON...
EASTON                               36.0                    
SNOQUALMIE PASS 2.6 SSE              18.5                    
LUCERNE 9 W                          12.0                    
STEVENS PASS                         10.0                    

...WYOMING...
SUGAR LOAF CAMPGROUND                16.5                    
BATTLE LAKE 2 E                      15.0                    
WHISKEY PARK 1 NW                    14.4                    

...Selected preliminary Storm Total Rainfall in inches from 400 AM
PST Wed Dec 22 through 1200 PM PST Fri Dec 24...

...CALIFORNIA...
LYTLE CREEK 2 WSW                    7.66                    
BIG BEAR LAKE 1 E                    6.03                    
MT SAN JACINTO 1 S                   6.03                    
PALOMAR MOUNTAIN 3 NNE               5.89                    
OAK VIEW 0.7 NE                      4.96                    
GOLETA 3.7 WNW                       4.52                    


Over the next several days, the upper-level trough over the West
is expected to remain locked in place and slightly strengthen
through the weekend. Multiple rounds of heavy mountain snow are
likely, with several feet of snowfall accumulation forecast across
the Sierra-Nevada, Cascades, and northern California mountains.
Falling snow levels may allow for locally moderate snow near sea
level across the Northwest, especially late Saturday through
Monday. The foothills and elevated valleys of California will also
see light to moderate snow this weekend and next week. Travel will
remain dangerous and is discouraged, especially along mountain
passes where long duration closures are likely. Dangerous
avalanches are also likely in the Sierra, Washington Cascades,
Northern Rockies, and Wasatch.

The next Storm Summary will be issued by the Weather Prediction
Center at 100 PM PST Sat Dec 25 2021. Please refer to your local
National Weather Service office for additional information on this
event.

Snell