Multi-day snowstorm to slam western US (with forecast video)

Trucks on snowy road in Washington state.

A prolonged stretch of wintry weather begins today, Dec. 11, in the mountains of the Pacific Northwest, the northern Rockies and other high elevations of western states. Disruptions are likely to affect transportation and freight movement, in addition to local and regional supply chains and business operations, especially in the higher terrain. When it’s all said and done, some areas could be buried in 4 feet of snow.

The first round of snow – confined mainly to the mountains of Idaho, western Montana and northeastern Nevada – will move into western Wyoming this afternoon, Dec. 11, fading this evening. But a persistent flow of moisture off the Pacific Ocean will crank up across the region later tonight, continuing at least into Friday, Dec. 13. This, combined with impulses developing in the jet stream, will result in several periods of moderate to heavy snow.

Snowfall amounts

Total snowfall accumulations in the higher elevations of Washington state, Oregon, Idaho, Montana and Wyoming will be in the 10- to 20-inch range, with some of the highest peaks getting slammed with 2 to 4 feet of total snow over the next few days.

More specifically, the National Weather Service (NWS) is expecting accumulations of 2 to 4 feet above 4,500 feet in elevation for many parts of the Cascades in Washington state; 12 to 24 inches between 3,500 and 4,500 feet; and 3 to 6 inches between 3,000 to 3,500 feet. This affects areas such as Mount Baker Ski Area, Stevens Pass (US-2), Snoqualmie Pass (I-90), Paradise on Mount Rainier and White Pass (US-12). Locations near the Cascade crest could see up to 3 feet of total snowfall, with 15 to 30 inches in the Cascades of southern Washington, including the Mount St. Helens area.

The Olympic Mountains in Washington, as well as adjacent valleys, will see 3 to 6 inches between 3,500 and 4,000 feet. This includes Hurricane Ridge.

The Cascades of Oregon could get slammed with 12 to 24 inches of snowfall, with higher accumulations above 5,500 feet. This would include spots like McKenzie and Santiam passes.

Impact on freight

Strong winds may accompany the storms at times, adding to the likelihood of transportation disruptions on the roads and rails, as well as in the air. Intense snowfall rates plus blowing snow may create occasional whiteout conditions. The interstate most likely to be impacted is probably I-90. However, portions of I-15 may also be treacherous.

SONAR Infrastructure (left-hand side), Critical Events (right-hand side): Wednesday, Dec. 11, 2019, 10:00 a.m. EST

The target areas for heavy snowfall are highlighted in Critical Events on the right-hand side of the FreightWaves SONAR map directly above. Right now no major assets in the region, such as airports or oil facilities, are at risk of significant disruptions. These assets are mostly located in valleys and major metropolitan areas that will be too warm to get snowed in. However, minor service interuptions are possible.

Road and rail conditions will be the main concern. Union Pacific (NYSE: UNP) and BNSF (NYSE: BRK.A), owned by Berkshire Hathaway, are the two largest rail freight carriers in the U.S. They both have tracks that are in the paths of the western snowstorms this week. These are in SONAR Infrastructure on the left-hand side of the map directly above.

The latest SONAR data, as of this morning, shows outbound tender volumes (OTVI) on the downslide over the past week in the Northwest freight markets of Seattle, Portland, Pendleton and Medford (see chart below). This means less freight for carriers has been available in these markets. Meanwhile, the markets of Twin Falls and Spokane are more promising, with increasing amounts of freight available. Truckers trying to pick up loads in these two markets may have to find alternate routes if they want to avoid the parade of snowstorms about to hit the region. 

SONAR tree map: Outbound Tender Volume Index (OTVI), weekly percent change

Other areas of heavy snowfall this week

Interior portions of the West will also see their share of snowfall through Friday, Dec. 13 or Saturday, Dec. 14, depending on location. Total snow accumulations of 12 to 24 inches are possible in the higher elevations of western Wyoming, with 8 to 16 inches in the lower slopes, and wind gusts up to  40 mph. This includes Yellowstone National Park and Jackson.

The foothills of the Wasatch Mountains in Utah could see 12 to 24 inches of snowfall, with higher amounts in the tallest peaks.

Heavy snow will also hit the northern Idaho Panhandle, mainly above 3,000 feet, in addition to areas above 4,000 feet in the central Idaho Panhandle. Total accumulations of 8 to 14 inches will be common, with local amounts of 20 inches on the highest elevations and winds gusting as high as 40 mph. Be particularly careful on Schweitzer Mountain Road and over Dobson and Lookout passes.

Last but not least, look for relatively minor accumulations of 3 to 5 inches of snow above 3,000 feet in northwestern Montana, with mixed precipitation and a glaze of ice possible below 3,000 feet. This includes Thompson Falls, Libby and Eureka.

Have a great day, and be careful out there!