Authorities say there is 'no possibility' of bringing the fire under control yet as the Santa Ana winds and dry weather conditions worsen the situation. Photo: Reuters

Tens of thousands of people are under evacuation orders as the blazes rage - and 1,400 firefighters have been deployed to respond.

I've never seen a day like this - residents watching the flames don't know where to go, our reporter in LA says.

The Santa Ana winds and dry weather conditions are worsening the situation, as authorities warn there is "no possibility" of containment yet.

Dramatic videos show bulldozers pushing cars out of the way to give firefighters access to one scene and flames ripping through homes.

The Santa Ana winds will – in the short term – increase slightly during the early to mid-morning local time in Los Angeles.

Gusts generally will be around 50-60mph (80-100km/h) but locally up to 100mph (160km/h) over portions of the higher ground.

The other weather factor critical to wildfires is the relative humidity – or how dry the air is - which is also very low at the moment at 10-20%. But this is likely to fall even further to 5-10% after sunrise. In other words, it will get even drier.

Local forecasts from the National Weather Service are predicting there could be localised extreme conditions near the Santa Ana mountains in Orange County. Additionally, a critical fire notice will extend towards San Diego.

Any new fires starting in the early morning will spread quickly.

The good news is that the wind will start to ease slightly during Wednesday afternoon, with the most extreme fire weather conditions slightly improving.

However, it will stay rather breezy so firefighting will still be difficult in some areas.