There’s already plenty of snow on the ground in the Sierra Nevada Mountains of California, but much more is on the way. A massive two-day storm, powerful even by Sierras standards, could dump several feet of snow across the mountain range from Wednesday through Thursday. Some roads will likely have to be closed, delaying freight movement through the area.
Storm Setup and Development
The first Pacific storm is currently producing light to moderate snowfall, which may intensity tonight. Travel impacts will become increasingly likely across the Sierra passes in northern California as precipitation increases.
The main event is still on track for later Wednesday into Thursday as a strong Pacific low pressure system moves across the region. Precipitation and wind will increase even more by Wednesday afternoon as the surface pressure gradient increases. The gradient is the change in pressure between the approaching low and the receding high pressure over the Rockies. The bigger the pressure difference, the stronger the winds.
With strong winds and snowfall rates possibly exceeding 2 inches per hour, blizzard conditions will be possible into Thursday evening.
Snowfall and Wind Forecast
The largest snowfall totals, mainly above 6,000 to 7,000 feet, are expected in the highest elevations of eastern Shasta County and the Lassen National Volcanic Park areas, as well as Mono County, the greater Lake Tahoe area (including Truckee), Kings Canyon National Park to Yosemite National Park, the eastern Sierra slopes (Aspendell to Whitney Portal), and the Mount Shasta region. Accumulations of three to five feet will be common across these areas.
Brendon Rubin-Oster, a meteorologist with the National Weather Service (NWS) in Sacramento, tells FreightWaves that even for a multiple-day storm this one will be pretty extraordinary when it’s all said and done, especially compared to other storms so far this season.
“Single-day storms often bring one to two feet of snow to the northern Sierras,” says Rubin-Oster. “But this two-day storm will be upper echelon, with up to six-foot totals possible in some areas.”
He also says there may be isolated accumulations of seven feet, almost as tall as the tallest current NBA players.
To make matters worse, wind gusts could reach 60 mph from Kings Canyon to Yosemite, and in the Mount Shasta region, with potential for downed trees and power lines.
Impacts on Travel
Very slick roads, heavy snowfall, strong winds, and blowing snow will make it tough for truckers to get through the Sierras during this storm. Deadheading or hauling light loads will be very risky, and even carrying full loads will be difficult. With a storm of this magnitude, Rubin-Oster says some passes will probably be closed at some point, possibly for several hours, in order for snow to be plowed.
Routes likely to give drivers the most problems are the following:
I-80 over Donner Pass
US-50 over Echo Summit
US-395 above 7,000 feet (Mono County)
US-97, including the city of Tennant
CA-3 south of Callahan
CA-88 over Carson Pass
CA-89 near Snowmans Summit and Dead Horse Summit
West of CA-89 (greater Lake Tahoe area)
Sawyers Bar Road
Check chain laws here for the latest updates on winter driving.
Impacts on Freight Movement
Loads being moved through the Sierras typically have to go through Reno, Nevada. Freight volume into Reno has been increasing lately, surpassing its most recent peak from late November. Based on FreightWaves SONAR data shown in the chart below (Inbound Tender Volume Index), recent inbound volume is higher than the pre-Christmas average in December (inbound and outbound typically drop drastically at Christmas time). Carriers and drivers: if you’re planning to haul loads through the Sierras during the coming storm, keep in mind that there may be a bit more traffic than usual heading into Reno.
The storm that’s about to slam the high elevations of the Sierras will produce heavy rain and possible flooding in the lower elevations. Up to six inches could fall in the foothills, while the valleys could see up to three inches. Besides flooding, the deluge may cause mudslides and debris flows which could end up blocking roads.