Modified arctic air moved into the region followed by a series of moderate to strong upper level storm systems riding on a moist subtropical jet stream.  The result was widespread heavy snow and local high winds.  Freezing rain accumulated to between 1/4 and 1/2 inch over the lower elevations of northern Oregon.
Snowfall amounts for January 17-18 in inches include Lostine (5), 9 miles northeast of Service Creek (8), 5 miles north northwest of Service Creek (10), Lake Creek SnoTel (5), Ochoco Meadows SnoTel (5), 2 miles north northeast of Ione (4), 5 miles north of LaGrande (12), Ukiah (7), 9 miles north of Ione (4), Bend  (7.7), The Dalles (10), 2 miles west northwest of Bend (7.5), Wasco (14), 1 mile southeast of Flora (15), 5 miles north northwest of LaPine (6), 15 miles south southeast of Flora (21), Camp Sherman (16), 10 miles south southeast of Maupin (10), LaGrande (7), 3 miles east of Mosier (24), 10 miles north-northeast of Ukiah (8), 6 miles southwest of Kamela (8), 9 miles north of Elgin (13.1), 2 miles north of Meacham (10), High Ridge SnoTel (15), Weston (4), 1 mile east northeast of Cayuse (4), 5 miles south southwest of Chenoweth (10.2), Condon (15.4), Heppner (4), Athena (4), Milk Shakes SnoTel (12), 2 miles south southwest of Camp Sherman (14), Dufur (11.7), Granite (16), and 1 mile south of Black Butte Ranch (9), 12 miles southwest of Lexington (4), Moro (7.5), 4 miles south southwest of Bend (7.7), 2 miles north northeast of Condon (9), 1 mile north northeast of Three Rivers (6.5), 12 miles southeast of Joseph (22), Joseph (5), 2 miles east of Pendleton (4), 21 miles south of Imnaha (8.2),  2 miles east of Bend 6), 4-6 miles north of LaPine (12), 4 miles south southwest of Bend (9), 1 mile east of LaGrande (7), Union (5), 1 mile east southeast of The Dalles (7.5), 5 miles northwest of The Dalles (9.5), and Granite (16).
Wind gusts reported on January 18 in miles per hour include Colgate RAWS (80), North Pole Ridge RAWS (66), and Tepee Draw RAWS (58).
On January 19-20, another surge of subtropical Pacific moisture moved over the cold air with widespread mixture of precipitation. The lower elevations received freezing rain mixed at times with sleet and snow.  The higher elevations received heavy snowfall. The storm caused numerous vehicle accidents with injuries, downed tree branches, power outages, and closed roads, including Interstate 84, and also closed schools.
Ice accumulations reported in inches included Echo (.5), Ione (.25), 7 miles north northeast of Mikkalo (.38), Rufus (.25), Pendleton airport (.25), Umatilla (.25), Pendleton (.38), Athena (.25), 2 miles southeast of Mosier (.5), and Lexington (.38).
Snow accumulations reported in inches included High Ridge SnoTel (8), Seneca (6), Lake Creek SnoTel (6), Rock Springs SnoTel (6), and Starr Ridge SnoTel (6).

Heavy Snow in EAST SLOPES OF THE OREGON CASCADES, OREGON
From 17-JAN-12 02:00:00 to 18-JAN-12 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in EASTERN COLUMBIA RIVER GORGE, OREGON
From 17-JAN-12 19:00:00 to 18-JAN-12 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in FOOTHILLS OF THE NORTHERN BLUE MOUNTAINS OF OREGON, OREGON
From 17-JAN-12 16:00:00 to 18-JAN-12 06:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Heavy Snow in FOOTHILLS OF THE SOUTHERN BLUE MOUNTAINS OF OREGON, OREGON
From 17-JAN-12 18:00:00 to 18-JAN-12 06:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Heavy Snow in JOHN DAY BASIN, OREGON
From 17-JAN-12 21:00:00 to 18-JAN-12 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in LOWER COLUMBIA BASIN, OREGON
From 17-JAN-12 20:00:00 to 18-JAN-12 07:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in NORTH CENTRAL OREGON, OREGON
From 17-JAN-12 13:00:00 to 18-JAN-12 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in NORTHERN BLUE MOUNTAINS, OREGON
From 17-JAN-12 14:00:00 to 18-JAN-12 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

Heavy Snow in OCHOCO-JOHN DAY HIGHLANDS, OREGON
From 17-JAN-12 12:00:00 to 18-JAN-12 16:30:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

Heavy Snow in SOUTHERN BLUE MOUNTAINS, OREGON
From 17-JAN-12 13:30:00 to 18-JAN-12 13:30:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

Heavy Snow in WALLOWA COUNTY, OREGON
From 17-JAN-12 13:30:00 to 18-JAN-12 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in OCHOCO-JOHN DAY HIGHLANDS, OREGON
From 19-JAN-12 15:00:00 to 20-JAN-12 10:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

Winter Storm in EASTERN COLUMBIA RIVER GORGE, OREGON
From 19-JAN-12 01:00:00 to 20-JAN-12 01:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in FOOTHILLS OF THE SOUTHERN BLUE MOUNTAINS OF OREGON, OREGON
From 19-JAN-12 03:00:00 to 19-JAN-12 13:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: County Official

Winter Storm in FOOTHILLS OF THE NORTHERN BLUE MOUNTAINS OF OREGON, OREGON
From 19-JAN-12 02:00:00 to 19-JAN-12 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Winter Storm in LOWER COLUMBIA BASIN, OREGON
From 19-JAN-12 04:00:00 to 19-JAN-12 17:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

High Wind in EAST SLOPES OF THE OREGON CASCADES, OREGON
From 18-JAN-12 04:00:00 to 18-JAN-12 14:00:00 (PST-8)
Magnitude: 70.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

Heavy Snow in GRAND RONDE VALLEY, OREGON
From 17-JAN-12 21:00:00 to 18-JAN-12 12:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter