Active weather pattern the remainder of this week and into next week, bringing widespread moderate to heavy rainfall, high elevation snow, and possible flooding concerns. Flood Watch from this afternoon through late Saturday night. Winter Weather Advisory from 4 AM Saturday to 4 AM PST Sunday.
Discussion
Moisture from the storm continues to stream over the region producing light rain this morning. There will be a chance within the valley for places to have a break at times from the rain during the day but the far north end of the valley, coastal mountains, and western slopes should continue to receive rain throughout the day due to orographic influence.
Have kept the flood advisory the same but valley threat areas look to occur more on Saturday than tonight. Some of the foothills may start to see some issues with small creeks tonight with all the orographic precipitation slowly building up. The valley’s potential for flooding concerns looks more likely to start late tonight over the far north end of the valley and on Saturday to the south.
Lots of orographic influence and snow melt should bring sharp rises to rivers and streams below the snow level with some messy slushy streets within the remaining snow pack.
Winds will be breezy through Saturday morning with gusts up to around 30 mph for the valley.
New Years Eve celebrations continue to indicate a dry trend especially over the northern and western areas for the mid to late evening hours.
For the Motherlode and adjacent mountains showers look to continue well past midnight. Behind this system New Years Day is looking dry with just a few lingering early morning showers over the mountains south of highway 88.
North winds behind the front developing late Saturday night will help to prevent any fog from forming Sunday morning. A breezy northerly wind will likely develop during the day.
Monday a weak system will move in during the day with timing still not certain on morning or afternoon hours. Snow levels do look much lower starting out around 2000 feet over Shasta County transitioning to 3500 feet for the western slopes. Generally looking at 5 to 6 inches above 5000 feet at this time with lessor amounts below that. Rainfall amounts for the valley look to be around a third of an inch or less at this time.
Extended Discussion (Tuesday through Friday)
Clusters favor a weak ridge over the region on Tuesday with the pattern transitioning to a through Wednesday and Thursday. So at this point during the daytime it is looking mostly dry with a potential warm front moving through Tuesday night.
Timing with at least a moderate storm system remains uncertain with the European favoring an earlier landfall than the GFS but clusters are indicating the potential for the earlier landfall. While these storms don’t look as wet or as strong as this current system, cold air should bring lower snow levels next week and winter travel problems could be an issue at times.