February 8, 2020 – Cooler this weekend with windy conditions. A few light Sierra snow showers possible tonight and Sunday. Dry next week except a threat of showers Friday.
Discussion
Short wave trough and associated surface boundary pushing into NW interior NorCal today. Some light echoes aloft on 88-D with the baroclinic zone but not reaching the ground attm. Given storm trajectory from B.C., moisture is limited. As trough digs into the area today, cooler air is ushered in. High temperatures forecast to be about 5 to 15 degrees lower than Friday. Wind begins to increase this afternoon over portions of the CWA.
Upper trough continues to dig over CA next 24 hours, developing closed low tomorrow. Resultant cyclonic upslope flow will lead to a threat of snow showers over the Sierra Nevada tonight and Sunday. Little to no accumulations are expected. Surface wind speeds continue to ramp up tonight into Sunday morning. Wind advisory in effect for large portions of the forecast area Sunday. Timing may need to be adjusted earlier in the Northern Sacramento Valley and Coastal Range, as current progs suggest wind advisory criteria could be met sooner than advertised there. Will continue to monitor for now. Widespread sustained 20 to 35 mph winds can be expected Sunday, peaking in the afternoon, with local gusts up to 50 mph in the Central Valley and locally to 60 mph or higher in the mountains. Little change in max temps for Sunday in the Central Valley with mountain areas continuing to cool another 5 to 10 degrees.
Precip threat ends Sunday night as upper low drops into SoCal. Upper ridging then builds over the area early next week resulting in warming AMS. Breezy conditions continue over portions of interior NorCal Monday into Tuesday.
Extended Discussion (Wednesday through Saturday)
Wednesday eastern Pacific ridging continues with dry northerly flow. North to northeast winds continue but conditions should be less breezy than Tuesday. High temperatures are expected to be well above average with dry weather.
A gradual slight cooling trend is expected into the weekend as a shortwave trough drops down from western Canada. The exact track of the trough will determine if this is a mainly a dry, windy event or if precipitation is more of an issue. Overall, this does not look like a very wet event either way, with mainly the potential for some mountain precipitation and clouds and cooler temperatures for the weekend.