New CPC Outlook: Atmospheric River May Affect the West Coast Next Weekend, With a 40–60% Risk of Heavy Rain for Northern and Central California
The National Weather Service Climate Prediction Center (CPC) issued a new Week-2 hazards outlook on November 6, valid for November 14 to 20, and its updated key message the same day said possible atmospheric river activity could affect West Coast states.
According to the outlook, parts of southwest Oregon and northern and central California face a moderate risk of heavy precipitation on November 14 and 15, with probabilities of 40 to 60 percent. A slight risk of heavy precipitation, at 20 to 40 percent, extends through November 17 across the West Coast and into parts of the Southwest, the Great Basin and the Southern Rockies.
For high-elevation snow, the Klamath Mountains and the Sierra Nevada face a moderate risk of heavy snow on November 14 and 15. Through November 17, a slight risk of heavy snow covers high elevations of the Cascades, the Klamath and the Sierra Nevada, as well as parts of the Northern Intermountain, the Great Basin and the Central and Northern Rockies.
Forecaster Thomas Collow wrote in the outlook discussion that the ECMWF, GEFS and Canadian ensembles continue to depict anomalous troughing off the West Coast, with a potent surge of moisture at the start of the period keeping risks elevated for heavy precipitation, high-elevation snow and coastal winds. In its key message, the CPC advised the public to monitor local forecasts for safety alerts, avoid driving through flooded roadways, and use caution when traveling through high elevations.
Source: National Oceanic and Atmospheric Administration
Published by GSM · USA (original Chinese edition)
Photo: 图：加利福尼亚州内华达山脉的雪峰。Quintinsoloviev 摄，CC0，经 Wikimedia Commons。 / Photo: Snow-capped peaks of the Sierra Nevada in California. By Quintinsoloviev, CC0, via Wikimedia Commons.
