A dry air mass is bringing early morning cold to many areas of Southern California.
Frost advisories are widespread for inland valleys elsewhere in Southern California.
The cold air is expected to persist into Friday, when strong Santa Ana winds are expected to develop as surface high pressure builds in the Great Basin region.
The weather service said the strongest winds will occur along coastal slopes and foothills and through and below the mountain passes and canyons. Windiest locations could see 80 mph gusts.