Dozens of communities are now under mandatory evacuation orders in Southern California with evacuation warnings affecting dozens more as crews continued battling a pair of deadly wildfires in the region Friday.

A short reprieve in the strong destructive winds has granted firefighters an opportunity to curb the spread of the deadly Eaton Fire near Pasadena.

The most destructive wildfires in Los Angeles history Thursday have burned more than 54 square miles of land, destroyed thousands of structures and killed at least five people.

That’s leading to the creation of mountain waves, which arise when strong winds blow perpendicular to a mountain range. The waves shoot down the coastal side of the mountains, gaining speed along the way, and are more casually referred to as simple Santa Ana winds.

Dire warnings have been issued for the Los Angeles area, with a dangerous threat for the strongest wind event in more than a decade. Outages and extreme fire behaviours are major risks

The National Weather Service has issued a Red Flag waning for a wide swath of Southern California as Santa Ana winds are expected to bring dangerous fire weather to the region later this week.

Strong Santa Ana winds are hitting fire-ravaged Los Angeles on Friday morning, but the winds will relax later in the day and the red flag warning will end Friday night.

The Santa Ana winds will stick around into Friday morning as most of the region remains under a critical fire risk.The National Weather Service extended a red flag warning for much of the region until 6 p.