Come Monday is another Santa Ana wind event that will run into Wednesday, predominately affecting Los Angeles and Ventura counties.

Another round of Santa Ana winds has moved into Southern California and will spread south through San Diego County late Thursday. The additional dry air also is expected to worsen the region’s already very low humidity levels,

Red flag criteria is generally when relative humidity is at 15% or less, combined with sustained winds and/or gusts of 25 mph or greater. Both of these conditions must occur simultaneously for at least 3 hours in a 12 hour period, according to the NWS.

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.

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.

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.

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

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 fierce winds in the Los Angeles area subsided Friday, but critical fire weather conditions remain and red flag warnings are still in place.

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.