March 31, 2017 – Gusty north winds through this evening. Dry and warm conditions Saturday and Sunday except for a slight chance of showers northern mountains and Sierra Sunday afternoon and night. Next chance of light precipitation late next week with heavier precipitation possible next weekend. Wind Advisory from 8 AM this morning to 11 PM this evening.
Discussion
Northern California currently between an upper low pressure system over the southern Great Basin and building high pressure over the eastern Pacific. Northerly flow between the two systems combined with a 10 mb surface gradient from MFR to SAC bringing breezy north winds to northern California.
Central valley winds running in the teens this morning. Some higher elevations showing wind gusts in excess of 30 mph and expect these stronger winds to surface down into the valley later this morning.
Have issued a wind advisory for the valley and coast range through this evening after which surface and upper gradients should relax.
Warm and dry weather expected Saturday under upper level ridging with breezy but lighter north winds continuing. Warming airmass will bring daytime highs up to between 10 to 15 degrees above normal. A short wave trough moving through the Pacific northwest will flatten the ridge a bit on Sunday bringing a little cooler temperatures although daytime highs will remain well above normal.
By Sunday afternoon this shortwave will bring a slight threat of showers to the northern mountains with this threat shifting southward into the Sierra Cascade range Sunday night. Upper ridge axis shifts over the west coast on Monday bringing fair skies to the entire forecast area with breezy north winds continuing.
Extended discussion (Tuesday through Friday)
Models point to strong upper ridging over Interior NorCal through the first half of next week with dry weather and above normal high temperatures. Models have trended to a slower progression of the the ridging and upstream trough. Weather looks to remain dry through Wednesday.
Potential for atmospheric river to setup over the forecast area Thursday into the weekend.