April 13, 2020 – Dry weather with mild temperatures thru mid-week with local breezes at times. Cooler with a chance of mountain showers by the weekend.
Discussion
A few patches of high clouds continue to drop down into NorCal in northwesterly flow aloft, otherwise skies are clear early this morning other than a diminishing patch of stratus over the Motherlode. Current temperatures range from the upper 20s in the colder mountain valleys, to the upper 40s to mid 50s across the Central Valley.
Another vort dropping down from the north may spark a few showers over the Sierra Nevada south of Tahoe late today, otherwise generally dry and mild weather is expected over NorCal this week as the amplified pattern remains in place with strong ridging over the eastern Pacific and a trough to our east over much of CONUS. A series of stronger short-waves dropping down from the north may bring a return of mountain showers late in the week.
Locally breezy northerly winds will develop today across the Central Valley as surface gradients tighten. Gusts around 30 mph will be possible. Gradients become more easterly tonight with gustier winds expected to continue along the west side of the Sacramento Valley and pick up across the west slopes of the northern Sierra.
Extended Discussion (Friday through Monday)
Series of upper lows are forecast to dig through NorCal during the extended forecast period. Models variations exist with track of lows which result in some forecast uncertainty. Pattern suggest there will be a threat of precipitation at times, highest POPs during the afternoon and evening hours and mainly over the foothills and mountains. QPFs remain light with some light snow showers possible above 6000 feet. Above normal temperatures Friday cool to near normal by next Monday.