LA County supervisor calls for investigation about the slow evacuation of residents in one community as fires broke out across Los Angeles

The National Weather Service on Tuesday extended its red flag warning for Southern California until Thursday evening.

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.