A significant snowstorm will hit parts of the Rockies and Mountain West this week as the remnants of Tropical Storm Raymond send ample Pacific moisture into the region. The same storm will drench areas of the Desert Southwest.



The snowy side



The storm will begin cranking Tuesday afternoon, Nov. 19, dumping snow across the high elevations of the Sierra Nevada in eastern California, as well as the mountains of southern Nevada and southwestern Utah. This slow-moving storm will be a two-day event for many areas, marked by a sharp drop in temperatures. Snowfall should fade in most areas Thursday afternoon or evening, Nov. 21.



In the Sierra Nevada, snowfall will not likely affect truckers on I-80 between California and the Reno-Lake Tahoe area. The storm will hit south of there, making mainly mountain passes treacherous.



For the southern Sierra Nevada and Kern County mountains, total accumulations will range from only a few inches to as much as nine inches above 6,000 feet in elevation. This includes the cities of Devils Postpile, Florence Lake, Lake Thomas Edison, Tuolumne Meadows, Bass Lake, Fish Camp, Wawona, Shaver Lake, Camp Nelson, Giant Forest, Lodgepole, Grant Grove, Johnsondale, Lake Isabella, Tehachapi and Grapevine. Snow levels could be as low as 5,000 feet in the Tehachapi mountains.



For the eastern Sierra slopes and White Mountains of Inyo County, California, in addition to the Sheep Range, Spring Mountains and Red Rock Canyon in Nevada, look for total snow amounts of 10 to 18 inches above 6,000 feet, with the heaviest amounts above 7,500 feet. All of the California and Nevada locations mentioned are under a winter storm watch.



Utah is in position to get slammed with the most snowfall from this storm, mainly in the mountains east of the I-15 corridor. It’s the first significant snowstorm of the season for this part of the Beehive State. But Charlotte Dewey, a meteorologist with the National Weather Service (NWS) in Salt Lake City, told FreightWaves it’s not unusual for mid- to late November.



“I would say we’re at right about the normal time of year when we start seeing higher snow amounts from winter storms,” Dewey said.



Dewey and her fellow Salt Lake City office meteorologists are forecasting total snow accumulations of 12 to 24 inches for the mountains of southwestern Utah, with localized spots receiving more than 24 inches. They have issued a winter storm warning for these areas, highlighted in the FreightWaves SONAR Critical Events map above.



Travel could be very difficult, especially on state routes. This includes UT-12 over Boulder Summit, UT-143 near Brian Head Resort, UT-148 near Cedar Breaks, UT-153 between Beaver and Junction, and UT-14 between Cedar City and US-89.



While generally one to two feet of snow is nothing to sneeze at, Dewey said the storm would much be worse if it happened over a shorter time period.



“One to two feet in the mountains here is not a ton of snowfall,” she said. “In a shorter duration time period, that would be more significant, but this is spanning 24 to 36 hours.”



Nonetheless, the storm may at least disrupt local and regional supply chains in southwestern Utah, as well as the previously mentioned areas of California and Nevada. The main concern will be road conditions, with closures possible. This storm will not likely damage or disrupt operations at any major assets such as airports, sea ports, railroads or oil facilities.



Also, carriers will need to make sure their drivers follow “protect from freeze” procedures due to the quick drop in temperatures just prior to and during the storm. Highs will fall from the 40s on Tuesday to the lower and mid-30s Wednesday and the 20s Thursday. Lows will be in the teens by Thursday morning.



Other parts of Utah will also get their share of snowfall. Places such as Scofield, Cove Fort, Koosharem and Fish Lake will see storm totals of six to 12 inches. Accumulations up to 18 inches are possible across the central Utah mountains. Travel could be very difficult, especially near I-70 at Salina Summit, Daniels Summit, Indian Summit and the Lake Mirror Highway.



Heavy snowfall is also possible in the mountains of Wyoming, western Colorado and New Mexico.



The rainy side



The same storm that will dump heavy snowfall in the Mountain West will douse lower elevations of the region and the Desert Southwest. Periods of heavy rainfall on Tuesday and Wednesday, Nov. 19 and 20, could produce flash flooding in southwestern Utah, as well as from southeastern California to the Phoenix metropolitan area. Rainfall totals could reach two to five inches, and the NWS has posted a Flash Flood Watch for these areas. Phoenix Sky Harbor International Airport (ICAO code: PHX) is the main asset in the watch area. There is potential for roadblocks along the I-8 and I-10 corridors.