December 27, 2019 – Dry weather into the weekend with light showers possible on Sunday. Dry conditions return for the end of the year into the new year.
Discussion
Upper level ridge will continue to build into NorCal today. This will continue quiet weather into the weekend. Clear skies will bring cold temperatures this morning with valley lows in the low to mid 30s and teens in the mountains. North winds will keep our fog potential very low this morning and overall relative humidity is too low to see widespread frost but can`t rule out some patchy frost across the area. Otherwise nice conditions are expected for today with some passing highs clouds mid afternoon into the evening. With less wind expected tonight we should see strong radiational cooling with overnight lows a few degrees cooler.
Cloud cover will be on the increase on Saturday as we see a trough approach from the north northwest. This trough will push a cold front through the area during the day on Sunday and bring shower chances starting Sunday morning in the Coastal Range. Shower chances will continue to overspread the area during the day Sunday. Overall this system will not have a lot of moisture but it has been trending upward as of recent. Due to this trend have upped QPF a bit with generally .15″ to .30″. Snow levels look to be between 4000 and 5000 feet but will be locally lower over Shasta County especially Sunday afternoon/evening. A few inches of snow is expected mainly above 4500 feet. The trough will dig south into SoCal Sunday night into Monday with a ridge building in over the top of it. This will bring us breezy north winds Monday but dry weather. Great weather is expected for New Year’s Eve.
Extended Discussion (Tuesday through Friday)
High pressure looks to be the dominate feature fore the extended period. The eastern Pacific ridge will start to nudge its way over northern California on Tuesday, with the northerly winds likely decreasing later in the day. Ensemble guidance keeps most of the region dry through the week with the ridge potentially weakening on Friday. NBM guidance shows some showers being possible over the Cascades/Shasta Co Friday, but most of the area should remain dry.