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.

Another round of fire weather is expected to last for much of this week as residents return home to the Palisades and Altadena neighborhoods to inspect the devastation.