Wildfires have been raging in California all last week and they are expected to continue into next week as well. These wildfire events are caused by many factors all attributed to the weather and changing climate of our planet. Here’s how it happens.
Setup
It all starts with hot and dry weather due to little rain. Overall, for summer and fall the weather in California has been running very dry with most fire prone areas running at below normal precipitation the last few months.
California temperatures have been holding well above normal. This past summer and fall presented one of the hottest periods on record for the state. This makes for very good weather for wild fires to start.
As for ignition, it is theorized that about 84% of wildfires are started by humans. This could either be on purpose or by accident or arson or campfires. Or they could also be caused by just a downed power-line or a tossed cigarette.
Spread of the Fires
These fires really start to spread due to a phenomena called Santa Ana winds.
These Santa Ana winds are caused by troughs dipping down into the western USA. These troughs create a strong pressure gradient between the base of the trough and the coast of California. This pressure gradient creates winds that slope down the Sierra Nevada mountain range. These down sloping winds are associated with dry air and warmer temperatures which are both causes for fire.
When even the smallest fire starts it can being to rage with help from these down sloping winds and push towards the coast.
Wildfires have been raging in California all last week and they are expected to continue into next week as well. With a combination of all of these weather factors, there are huge implications for even the smallest fires. Dry air, hot weather, and strong winds are all culprits for these dangerous wildfires.
