Snow may join the rain this week as a "colder air mass looms," the National Weather Service reported Monday, as the California Department of Transportation was responding to a landslide that closed Highway 101 in northern Mendocino County.
According to an update from Caltrans at 11 a.m. Feb. 3, Highway 101 was "still fully closed south of Leggett (PM 85.5) in Mendocino County due to an active slide. Caltrans crews are on scene working to clear the roadway. Motorists can use Route 271 as a detour." At the time, there was no estimated time of reopening provided.
As for the rain that is expected to continue falling, "warm moist air that is being siphoned to the southern zones ... will be displaced by a cold airmass with less moisture," staff at the Eureka office of the National Weather Service reported in the Forecast Discussion prepared for Feb. 3, adding that "rain continues with the possibility of low elevation snow and mixed precipitation as a colder air mass looms."
On Monday, the NWS forecast explained that "the Atmospheric River continues to bring rain and high elevation snow, but this will be interrupted as the cold core low pressure system continues southbound, (bringing) low elevation snow and possibly mixed precipitation to the coastal areas by mid-morning Tuesday. That said, a second round of rain is due (Monday) through midweek which adds to the complexity as tropical moisture will dominate the shallow cold air at the surface, (which) will help drop snow levels quickly by (Monday) night into Tuesday."
"Snow levels will drop first and most consistently on the western side of the coastal mountains," the forecast continues, noting that "freezing levels will filter inland and further south as far as northern Lake County through Tuesday into Wednesday. (Then) a second, more consistent pulse of snow showers is expected Tuesday into early Wednesday, bringing more snow to highway passes and pushing a bit further south. The risk of snow and rain will continue through the week with the current most likely forecast showing moderate snow down to 2000 feet early Thursday."
The NWS forecast for the Ukiah Valley the next few days is:
* Tuesday: Showers, mainly before 4pm. High near 51. Chance of precipitation is 80%. New precipitation amounts between a half and three quarters of an inch possible.
* Wednesday: A 50 percent chance of showers. Partly sunny, with a high near 52. Calm wind becoming southwest around 6 mph in the afternoon. New precipitation amounts of less than a tenth of an inch possible.
* Thursday: Showers. High near 49. Chance of precipitation is 90%. New precipitation amounts between a half and three quarters of an inch possible.
* Friday: Showers likely, mainly before 10am. Partly sunny, with a high near 50.
* Saturday: Sunny, with a high near 54.