Marine Weather and Tide Forecast for Penn Valley, CA

DISCUSSION
Today-Monday: Scattered high clouds are being observed over portions of Northern California this afternoon as a deepening offshore trough approaches the SoCal coast. As a result, periods of breezy onshore wind will develop today with west to southwest gusts 15 to 25 mph mainly through the Delta. Onshore flow increases on Monday with Delta gusts up to 30 mph and breezy winds up into the Sacramento Valley. Additionally, as this low tracks further onshore, it will bring chances for limited precipitation and isolated thunderstorms (less than 10%) Monday afternoon/evening. Highest potential exists south of US 50. Primary impacts from any thunderstorms that develop will be new fire starts from isolated lightning strikes and gusty outflow winds.

Tuesday-Thursday: As the trough weakens and moves further into the Desert Southwest, Northern California will remain under split flow aloft as heights increase. As a result, onshore flow influence will weaken heading into midweek as temperatures trend warmer. The warmest temperatures of the week are currently expected on Thursday, with areas of Moderate HeatRisk in the Delta and southern Sacramento and northern San Joaquin valleys, however there is still some uncertainty regarding how warm temperatures will be. Relative humidities trend lower during this time as well.

Friday-(next)Sunday: Heading toward the end of week/weekend period, offshore troughing is forecast to dig down from the Gulf of Alaska. This will induce stronger onshore winds through the Delta/Valley and enhanced gap flow through the Coast Range. This system will also bring the potential for unsettled weather in the form of light shower chances over Shasta County mountains on Friday. Temperatures are also forecast to trend cooler Friday into the weekend with Valley highs in the 80s.



AVIATION
VFR conditions expected through 18z Monday. Winds at the TAF sites will be less than 12 kts, but west-southwest gusts to 15-20 kts are possible in the Delta after 23Z Sunday. Gusts then increase up to 25 kts after 06Z Monday.



STO WATCHES/WARNINGS/ADVISORIES
None.