A powerful atmospheric river is expected to bring significant moisture to the West Coast during the second week of November, with NOAA warning of potentially heavy precipitation, mountain snowfall, and damaging coastal winds.
In a November 2 Key Message, NOAA’s Climate Prediction Center pointed toward November 10-12 as the period of greatest concern, with several inches of precipitation possible across parts of the West Coast. While lower elevations could experience flooding, higher elevations are expected to see substantial snowfall that could benefit ski resorts preparing for the winter season.
Washington Cascades Face Highest Snow Risk
The Washington Cascades are currently in the bullseye for the incoming storm. NOAA has identified a high risk, defined as greater than 60 percent, of heavy snowfall across the range between November 10 and 12. The moderate risk of heavy snow extends southward through the southern Cascades, Klamath Mountains, and Sierra Nevada, with the threat continuing through November 14.
The forecast also identified a slight risk of heavy snowfall across a much broader area of the Far West and Rocky Mountains during the same general period. This could bring additional early-season snowfall to mountain ranges farther inland, although specific accumulation forecasts have not yet been provided.
Flooding and High Winds Also Possible
The precipitation threat extends across much of the West Coast, with a high risk of heavy precipitation from northern California through the Pacific Northwest between November 10 and 12. A moderate risk stretches into central California and continues through November 14.
Lower elevations could experience flooding, particularly in areas that have recently dealt with significant rainfall. Coastal communities should also prepare for potentially strong winds, with NOAA identifying a moderate risk of high winds along portions of the West Coast through November 14.
Flooding and high winds present a serious hazard, but the potential for substantial mountain snowfall is encouraging news for resorts, skiers, and snowboarders as we head deeper into November. Further forecast updates should help clarify which mountain ranges and ski areas stand to benefit most from the incoming system.