... First widespread frosts of the season possible late in the week across inland areas...
A deep trough of low pressure will develop over the Great Basin later this week. Although the cold air in association with this system will only clip northwest California... the resulting airmass is likely to be very dry. The combination of dry air and longer nights will result in cold overnight temperatures in valleys and along the coast. Frost is likely Thursday night and Friday night for protected inland valleys... where readings may plummet to the lower to middle 30s. Along the coast... temperatures may drop into the middle to upper 30s in areas protected from the wind.
Those wishing to protect temperature sensitive vegetation should consider those preparations at this time and keep informed of later forecasts and potential advisories in subsequent days.
Thursday
Special Weather Statement