The strongest winds were expected to whip across the passes and canyons of Los Angeles and Ventura counties, producing gusts of at least 60 miles per hour in mountain areas and 50 mph in the valleys, according to the National Weather Service.
Wind gusts Tuesday morning were recorded at 72 mph at Chilao and 61 mph at Warm Springs -- both Los Angeles County mountain locales, the NWS reported.
Coinciding with the high Santa Ana winds, humidity will fall into the teens Tuesday, with "even some single-digit readings possible," the NWS warned in an advisory.
Conditions also lend themselves to wildfire because the vegetation that would fuel a blaze remains exceedingly dry, despite some recent rain, according to the NWS.
The winds will diminish Wednesday, but "warm and very dry conditions are expected to continue," the advisory said.
The red flag warning was scheduled to go into effect at 10 a.m. Tuesday and expire at 4 p.m. Wednesday along the coast; from Malibu to the Hollywood Hills, including downtown Los Angeles; in the San Fernando and Santa Clarita valleys; and in the Santa Monica Mountain Recreational area.
In all other mountain areas of Los Angeles and Ventura counties, including those that include the Angeles National Forest, the red flag warning was scheduled to take effect at 8 a.m. Tuesday.
The National Weather Service also issued a high wind warning for the mountains of Ventura and Los Angeles counties effective until 4 p.m. Tuesday. A less serious high wind advisory effective until Wednesday afternoon was issued for valley and coastal areas, including the Orange County Coast.
In the Antelope Valley, a freeze watch -- indicating that sub-freezing temperatures below 28 degrees are possible for at least two hours -- will be in effect from late Tuesday night through Wednesday morning.
Forecasters said northeast winds of between 25 and 40 miles per hour were expected Tuesday in mountain areas, including the Santa Monicas, gusting to up to 60 mph. Wind speeds in the other areas subject to the red flag warning were expected to be somewhat weaker.
Temperatures were expected to be relatively mild Tuesday -- in the high 50s in the Antelope Valley and the low 70s most everywhere else in the Greater Los Angeles area.
Temperatures were expected to rise by several degrees Wednesday and several more Thursday before taking a sharp dip Friday at the start of a cooling trend.
The Los Angeles Fire Department did not immediately declare red flag parking conditions in Los Angeles. Such a declaration restricts civilian parking on hilly streets.