Southern California is braced for "extremely critical fire conditions" caused by a new period of Santa Ana winds of up to 50 mph.

After a week in which two wildfires smothered multiple Los Angeles neighbourhoods, killing at least 25 people, the US entertainment capital and its surrounding counties remain in "particularly

The winds fueling Southern California wildfires form when a high-pressure system develops over the Great Basin in Utah and Nevada

Following a few days of quieter conditions, Santa Ana winds will strengthen again increasing fears of explosive fire growth

The Santa Ana winds are dry, powerful winds that blow down the mountains toward the Southern California coast. The region sees about 10 Santa Ana wind events a year on average, typically occurring from fall into January. When conditions are dry, as they are right now, these winds can become a severe fire hazard.

After a brief break on Sunday afternoon, another prolonged round of gusty Santa Ana winds is expected to develop, forecasters say.

Easing winds delivered a brief but much-needed reprieve to firefighters Tuesday as they battled two massive blazes burning in the Los Angeles area, and the National Weather Service pushed back its unusually dire warning of critical fire weather until early the following day.

After killing at least nine people, the Palisades Fire continues to burn as residents remain under evacuation orders and warnings, with the next Santa Ana wind event continuing fire danger.

Millions Southern Californians faced new wildfire warnings Tuesday, and tens of thousands saw their power shut off as strong winds blew across the parched landscape around Los Angeles where two massive blazes have been burning for a week.