The National Weather Service in Sacramento has issued a forecast warning of periodic precipitation and breezy conditions continuing through the end of the weekend and heading into next week, as the region braces for a series of incoming weather systems. According to the area forecast discussion of NWS, intermittent rain showers have been primarily affecting areas south of Interstate 80, with the presence of low stratus and fog being a concern across the Valley.
While there is "some uncertainty of when the next weather system begins," forecasters predict variations in the onset from late Sunday morning to mid-Sunday afternoon. In preparation for the subsequent burst of rainfall, expected to persist through Sunday night into early Monday, they project between 0.10-0.50 inches of rain for the Valley and up to 1.00 inch in the mountains and adjacent foothills. Alongside showers in the Sierra, the weather service underscores an Excessive Rain potential for certain regions on Monday and particularly across the Sierra foothills on Tuesday, as per the National Weather Service.
Another weather wave is set to introduce a colder, wetter dynamic by Monday late morning, with snow levels anticipated to drop as low as 5,000 feet over the Sierra come Tuesday afternoon. This apparently more potent system could yield 1 to 1.75 inches of rain in the Valley and up to 4 inches in the mountains, alongside the possibility of thunderstorms primarily affecting the Delta, Sacramento Valley, and nearby foothills. Travelers should note gusty south winds reaching 20-35 MPH across the Valley and foothills and as intense as 45-50 MPH over the Sierra Crest Monday night through Tuesday afternoon.
Concerning snowfall, officials expect moderate travel impacts come Christmas Eve due to snow accumulation above 6000 feet. Probabilities suggest a "50-90% chance of 8 inches or more above 6500 feet and 15-35% chance around 6000 feet," especially along and south of Highway 50. A short-lived cessation in stormy conditions could make for a clear Wednesday morning before another spate of rain and mountain snow enters the scene, slated to last from late Wednesday night into the weekend, as per the NWS report.
Into the extended forecast of National Weather Service from Thursday through Sunday, there's a consensus on the continuation of precipitation, with varying amounts depending on the region. The probabilities stand at a 20-40% chance for rainfall exceeding 2 inches in the Valley north of I-80, whereas the mountains could see higher chances of up to 90%. Differing opinions persist on snow totals, but chances indicate possibly greater than 6 inches of snowfall above 6000 feet. Daytime temperatures are expected to hold steady in the 50s and low 60s in the Valley, and between the 30s and low 50s across higher elevations. Drivers and holiday travelers are encouraged to stay informed on the latest weather conditions by visiting weather.gov/sto and checking road statuses on quickmap.gov.ca.us.
