A particularly dangerous situation red flag warning is in place from noon Monday to 10 a.m. PT Tuesday for a large portion of Ventura and Los Angeles counties.

Two major fires are still uncontained in the Los Angeles area with red flag warnings issued for Monday, meaning powerful Santa Ana winds will make conditions hard for crews to fight already devastating blazes.

NWS' 3:40 a.m. advisory indicates winds were blowing northeast at speeds between 25 to 35 mph, with gusts up to 60 mph.

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.

Forecasters expect Wednesday will be noticeably windier than Tuesday and firefighters warned that vegetation is critically dry.

Here's a guide to understanding "particularly dangerous situation" red flag warnings, containment, and other terms related to the devastating fires that have left much of the LA area in ruins.

A red flag warning due to wildfire danger will be in effect from 10 a.m. Monday to at least 10 p.m. Tuesday for inland valleys and mountain areas throughout the county, according to the National Weather Service.