The Weather Prediction Center
College Park, MD
Storm Summary Message
Storm Summary Number 2 for Western U.S. Winter Storm System
NWS Weather Prediction Center College Park MD
700 PM PST Mon Dec 13 2021
...Atmospheric River to bring significant heavy rain and snow to
California as a broader high wind threat continues across the
western and central U.S....
Winter Storm Warnings are in effect for the northern Coast Ranges,
Sierra Nevada, and Transverse ranges of California; the coastal
ranges and southern Cascades in Oregon; portions of the Sierra
Nevada and Great Basin in Nevada, the Sawtooth Mountains in Idaho,
central Utah and northeastern Arizona.
High Wind Warnings are in effect for the Southern Coast Ranges,
Transverse Ranges, and Peninsular Ranges of California, the Sierra
Nevada of Nevada, the Wyoming Basin, western Utah and northeastern
Arizona.
Winter Weather Advisories are in effect for northern portions of
the Cascades and Okanogan Highlands in Washington, the Coast
Ranges and Cascades in Oregon, northern Great Basin of Nevada,
Northern Rockies of Idaho and Montana and western Wyoming.
High Wind Watches are in effect for portions of eastern Utah; the
Sangre De Cristo Mountains and Eastern Plains of Colorado and New
Mexico; the Wyoming Basin; the High and Central Plains of the
Texas Panhandle and western Oklahoma, Kansas, and Nebraska, and
the Mid-Missouri Valley.
Wind Advisories are in effect for large portions of California,
Arizona, Nevada, southern Oregon and southwestern Idaho.
For a detailed graphical depiction of the latest watches, warnings
and advisories, please see www.weather.gov
At 600 PM PST...A broad upper-level trough continued to approach
the West Coast as of this evening. At the surface, a slowly
meandering frontal boundary extended across the western U.S., from
the northern Plains west through the Northern Rockies before
turning south through southeastern Oregon and Northern California.
Significant moisture associated with an Atmospheric River
continued to spread inland behind and across this boundary.
Several areas of snow showers were ongoing across the Northern
Rockies in Montana and Idaho, the Cascades of Washington and
Oregon, and the Sierra Nevada and Coastal Ranges of California. In
addition, a broad area of heavy rain continued along the West
Coast, with particularly heavy rain currently falling along the
Coastal Ranges of California.
...Selected preliminary Storm Total Snowfall in inches from 800 AM
PST Sat Dec 11 through 600 PM PST Mon Dec 13...
...CALIFORNIA...
CASTLE PEAK 25.0
SUGAR BOWL 24.0
SIERRA SNOW LAB 23.5
HOMEWOOD 22.0
SODA SPRINGS 1 ENE 18.7
KIRKWOOD 18.0
MOUNT SHASTA 6 ENE 13.0
...IDAHO...
DONNELLY 3 SSW 20.0
NEW MEADOWS 2 NNW 19.5
ELK RIVER 15.0
HORSESHOE BEND 11 SSE 13.0
PIONEERVILLE 9 ESE 12.0
BELLEVUE 1 WSW 11.0
HAILEY 2 NNW 10.0
ARCO 7.0
WOODLAND 1 E 6.5
...MONTANA...
DUPUYER 23 SW 12.0
NOXON 12 NE 12.0
...OREGON...
HALFWAY 9 NNW 18.0
CRATER LAKE 1 SW 16.0
TOLLGATE 13.0
CRESCENT 1 W 10.0
SUMPTER 6 N 9.0
HAYES HILL 6.0
...WASHINGTON...
WINTON 3 NW 14.0
LUCERNE 9 W 10.5
MAZAMA 2 NW 8.3
EASTON 6 NNW 7.0
STEVENS PASS 6.0
...Selected preliminary Storm Total Rainfall in inches from 800 AM
PST Sat Dec 11 through 600 PM PST Mon Dec 13...
...CALIFORNIA...
MOUNT TAMALPAIS 8.74
SCOTTS VALLEY 6.05
SCOTT CREEK 5.84
WOODACRE 5.84
BEN LOMOND 5.68
PARADISE 1.1 W 5.53
KENTFIELD 5.36
STRAWBERRY VALLEY 5.05
GASQUET 4.86
RED MOUND 4.56
DOWNIEVILLE 4.53
FLYNN PRAIRIE 4.37
DE SABLA 3.93
SPRING VALLEY 3.86
WHISKEYTOWN 1.6 S 3.80
AMERICAN HOUSE 7.6 SW 3.76
SIMS 3.51
ELMIRA 3.25
BLUE CANYON 3.18
ARNOLD 2.40
SAN FRANCISCO 2.37
SACRAMENTO 1.49
...OREGON...
SELMA 2.28
MURPHY 1 SSE 1.54
BANDON 3 NE 1.42
...Selected preliminary Peak Wind gusts in miles per hour earlier
in the event...
...CALIFORNIA...
JOAQUIN RIDGE 65
LAS YEGUAS 62
CHOLAME 57
DE LA CONCEPCION 52
...IDAHO...
GRANGEVILLE 2 N 60
WINCHESTER 5 NW 59
...MONTANA...
EAST GLACIER PARK 8 SE 92
BYNUM 14 W 86
WILSALL 17 NE 78
SUNBURST 75
DENTON 7 ENE 68
LIVINGSTON 2 WSW 68
ZORTMAN 10 ESE 65
GREAT FALLS 5 WSW 62
...OREGON...
LINCOLN CITY 93
YAQUINA BAY BRIDGE 78
HEBO 5 ESE 75
YACHATS 2 SE 72
ASTORIA 1 W 68
ROCKHOUSE RAWS 61
GARIBALDI 2 WNW 59
SALEM AIRPORT 47
PORTLAND 45
...WASHINGTON...
RICHLAND 22 NNW 78
WALLA WALLA AIRPORT 62
POMEROY 58
LOOMIS 5 S 49
SPOKANE SOUTH HILL 42
...WYOMING...
BORDEAUX 1 SSE 88
CASPER 2.1 SW 88
ARLINGTON 7 ESE 85
CLARK 80
CENTENNIAL 2 WNW 77
I25 - HAT SIX 77
RED CANYON - SOUTH PASS 72
CHEYENNE 1 NW 64
BIG HORN 17 WSW 60
GELNROCK 1 S 58
Heavy precipitation in the form of both rain and snow will
continue across California, Oregon, and the Great Basin through
the early week as an upper-level trough continues inland across
the western U.S. and the Atmospheric River brings in additional
surges of significant moisture. Broad, significant snow totals of
1-3 feet are forecast for the Cascades, Sierra Nevada, and Great
Basin mountains. Locally, some snow totals may exceed 3-6 feet in
the Sierra Nevada. The heavy rain threat will also continue
through the next couple of days. There is a Moderate Risk of
Excessive Rainfall for Monday for the Big Sur Coast of California
with a broader Slight Risk for the Southern Coast Ranges. Rainfall
of 5-8 inches is likely overnight bringing the threat of flash
flooding to the Coastal Ranges as well as debris flows across burn
scars. There is a Slight Risk of Excessive Rainfall for Tuesday
for portions of Southern California including the Los Angeles and
San Diego metro areas. Forecast rainfall of 2-4 inches is expected
along the higher terrain of surrounding mountain ranges, with 48
hours totals potentially approaching 3-6 inches. Debris flows
along burn scars in the area remains the primary impact. In
addition to the heavy precipitation, high winds will continue
across a broad portion of the western and central U.S. as the
frontal system and strong upper-level trough continue eastward,
from the West Coast tonight into the Central Plains by Wednesday.
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.
Putnam/Russell
Last Updated: 956 PM EST MON DEC 13 2021