####018007816#### ACUS45 KWBC 122113 SCCNS5 Storm Summary Number 1 for Northwestern U.S. Winter Storm NWS Weather Prediction Center College Park MD 100 PM PST Fri Jan 12 2024 ...Areas of moderate to locally heavy snowfall continue through the Rockies, Great Basin, and Pacific Northwest, with a renewed round of snow expected with an incoming Pacific System Saturday... Winter Storm Warnings are in effect for portions of the interior Pacific Northwest, northern/central Great Basin, northern/central California, and the northern/central Rockies. Blizzard Warnings are in effect for portions of southern Idaho. Ice Storm Warnings are in effect for portions of western Oregon. Winter Weather Advisories are in effect for portions of the northern Rockies, central Great Basin, and northern/central California. Wind Chill-related Warnings and Advisories are in effect for portions of the interior Pacific Northwest, northern Great Basin, and northern and central Rockies. Winter Storm Watches are in effect for portions of northwestern Oregon and southwestern Washington. Flood Watches are in effect for coastal southern Oregon and northern California. For a detailed graphical depiction of the latest watches, warnings and advisories, please see www.weather.gov At 1200 PM PST...A quasi-stationary frontal boundary was analyzed through portions of the central/northern Rockies and into the Great Basin and Pacific Northwest, tracing a path from southeastern Wyoming through southern Idaho and towards the Pacific Coast of northwestern Oregon. Surface observations indicated a colder, sub-freezing air mass resided along and to the north of this boundary and along, east of the Cascades. An even colder, Arctic air mass with temperatures well below zero was in place in the High Plains along the Rocky Mountains, beginning to slowly pass through the mountains and into the northern Great Basin. National Weather Service Doppler Radar showed several areas of moderate to locally heavy snowfall occurring across portions of the Wasatch mountains and northern Utah, southwestern Idaho including the Treasure Valley, the Blue Mountains of northeastern Oregon, and the Oregon Cascades. The precipitation remained rain so far along lower elevations of the Pacific Northwest to the west of the Cascades. Surface observations also indicated gusty winds between 20-30 knots, particularly in vicinity of the quasi-stationary frontal boundary. ...Selected preliminary Storm Total Snowfall in inches from 700 PM PST Thu Jan 11 through 100 PM PST Fri Jan 12... ...IDAHO... DEADWOOD RESERVOIR 12 NNE 11.2 FEATHERVILLE 9.0 GRANGEVILLE 8.0 LEWISTON 1 SE 7.0 NEW MEADOWS 2 NNW 6.0 OROFINO 5 NE 6.0 STANLEY 4.6 ALMO 4.0 SODA SPRINGS 3.0 BOISE 1 N 2.0 ...MONTANA... BIGFORK 3 ENE 9.5 HERON 3 NW 8.1 COLUMBIA FALLS 7.0 THOMPSON FALLS 1 WSW 5.2 GRANTSDALE 2 ENE 5.1 HELENA 2 W 4.7 NYE 14 W 3.0 BILLINGS 3 NNE 2.0 ...OREGON... ISLAND CITY 4 NNW 13.0 JOSEPH 5.5 ELGIN 10 N 5.0 PILOT ROCK 3.0 SISTERS 2 WNW 3.0 JOHN DAY 1 NW 2.5 ...WASHINGTON... STEVENS PASS 15.0 WENATCHEE 1 WSW 11.4 ANATONE 2 S 7.0 WHITE SALMON 18 N 7.0 SEQUIM 2 ESE 6.0 DAYTON 9 NE 4.5 PORT ANGELES 4.0 ...Selected preliminary Peak Wind gusts in miles per hour earlier in the event... ...IDAHO... MARION 17 WSW 73 MESONET POPLAR 2 WSW 61 JEROME 3 E 60 IDAHOME 2 NW 57 MESONET ALTON 4 SW 56 COLD WATER 2 WSW 56 POCATELLO 7 E 55 ...OREGON... VAN 14 ENE 68 MESONET DIAMOND 10 NE 61 MESONET BURNS 43 Additional snowfall in vicinity of the frontal boundary will continue through Saturday morning, with the highest totals focused on the Oregon Cascades, southwestern Idaho, and the Wasatch mountains of Utah. Here, there is high probability (70-90%) of 6 inches or more of additional snow. Lighter totals of around 1-4" are expected for surrounding lower elevations. Strong, gusty winds will continue to lead to blizzard conditions across southern Idaho. An approaching upper-level shortwave and accompanying surface low pressure/frontal system over the Pacific will reach the region early Saturday, bringing a renewed round of moisture coincident with the frontal boundary continuing to creep southward. This will lead to additional snowfall spreading both further southward into California, the Great Basin, and the central Rockies, and also bring wintry weather to lower elevations of the coastal Pacific Northwest. The highest snow totals are expected in the Oregon Cascades, Sierra, Wasatch mountains of Utah, and central Rockies in Colorado, where there is at least a moderate probability (40-60%) of more than a foot of snow through Monday morning. There is a high probability (70-90%) lower elevations of the northern/central Great Basin from eastern Oregon into southern Idaho and northern Nevada/Utah will see 4+" of snow, locally up to a foot. Lower elevations of southwestern Washington and Oregon to the west of the Cascades can expect areas of snowfall, generally between 1-4", as well as potentially significant icing (accretions up to 0.5"), most likely for the southern Willamette Valley. In addition to the wintry precipitation, bitterly cold wind chills will continue for areas of the northern interior Pacific Northwest/Great Basin, and there is also the risk of flooding with rain along the southern Oregon and northern California Pacific Coast. The associated upper-level system is also expected to bring winter impacts to the Mid-South by late Sunday, and potentially the Northeast next Tuesday-Wednesday. The next Storm Summary will be issued by the Weather Prediction Center at 100 PM PST Sat Jan 13 2024. Please refer to your local National Weather Service office for additional information on this event. Putnam $$