As a \u0022once-in-a-generation\u0022 firestorm has raged across nearly 90,000 acres in Southern California this week—covering an area about six times the size of Manhattan and forcing\u0026nbsp;more than\u0026nbsp;100,000\u0026nbsp;people to evacuate their homes—experts are warning how climate change is fueling fires on the West Coast.LA meteorologist Anthony Yanez tweeted that he has \u0022never seen\u0022 the wildfire threat index reach the designation for \u0022extreme,\u0022 as it did late Wednesday, and quoted Ken Pimlott, director of the California Department of Forestry and Fire Protection, who reportedly told NBC, \u0022There will be no ability to fight fires in these winds.\u0022I\u0026#039;ve never seen the purple \u0022extreme\u0022 threat issued. But this is where we find ourselves Thursday for the\u0026nbsp;#SantaAnaWinds. \u0022There will be no ability to fight fires in these winds.\u0022 Cal Fire Chief Ken Pimlott\u0026nbsp;#NBC4You\u0026nbsp;pic.twitter.com/2DcBAQxxS0— Anthony Yanez (@AnthonyNBCLA)\u0026nbsp;December 6, 2017Environmentalist and 350.org co-founder Bill McKibben indicated the elevated threat warning is a consequence of the \u0022hot new world,\u0022 a reference to an increasingly warming planet being caused by fossil fuel emissions and other human activity.For first time ever CA issues its most extreme wind warnings as vast fires rage: “We’ve never used purple before.” Hot new world https://t.co/bMl7dDn58n— Bill McKibben (@billmckibben) December 7, 2017Writing for\u0026nbsp;Pacific Standard earlier\u0026nbsp;this week, meteorologist Eric Holthaus notes\u0026nbsp;even though it\u0026#039;s still fire season in Southern California, \u0022the current conditions in Southern California seem exceptional.\u0022 Describing the largest of the region\u0026#039;s\u0026nbsp;five fires, he\u0026nbsp;writes:\u0026nbsp;The\u0026nbsp;Thomas Fire, first identified late Monday night, grew 30-fold in size in just three hours and advanced at a rate of more than an acre per second for 12 hours into neighborhoods in the cities of Santa Paula and Ventura. At the time of the fire, the National Weather Service rated the fire-related weather conditions as \u0022extremely critical,\u0022 its worst assessment level. Wind speeds near the fire were measured\u0026nbsp;near hurricane force.\u0022This week\u0026#039;s Southern California fires will add to an already disastrous fire season,\u0022 Holthaus concludes,\u0026nbsp;pointing to wildfires in Northern California that killed at least\u0026nbsp;44 people earlier this year and are collectively \u0022ranked as the worst fire disaster in California history.\u0022Images and videos from the fires continue to circulate virally on social media, especially from commuters and evacuees on the 405 and 101\u0026nbsp;highways. Officials were forced to\u0026nbsp;shut down\u0026nbsp;a section of the 101 early Thursday, which the\u0026nbsp;Los Angeles Times\u0026nbsp;reports left \u0022no more open routes between Santa Barbara and Ventura counties.\u0022This is the 101 Freeway. There are no more open routes between Santa Barbara and Ventura counties, according to CHP\u0026nbsp;https://t.co/aoaBApyzhy\u0026nbsp;pic.twitter.com/49DvRDoPGr— Los Angeles Times (@latimes)\u0026nbsp;December 7, 2017Not the typical morning commute...\u0026nbsp;pic.twitter.com/kJIOQeqsIK— A. Mutzabaugh CMT (@WLV_investor)\u0026nbsp;December 6, 2017Daniel Swain, a climate scientist at the University of California Los Angeles and writer of the\u0026nbsp;Weather West\u0026nbsp;blog, was among the group of experts who explained to The Verge how rain is essential to quenching the California wildfires, and how scientists believe climate change has contributed to below average rainfall in the region that is likely to persist into the future.\u0022By this time of year, usually, there\u0026#039;s been some rain that\u0026#039;s wetted things down,\u0022 Swain said, but in the current warm winter dry spell, \u0022it\u0026#039;s just as dry as it was in the summer months.\u0022From October to May, strong winds in the upper atmosphere, called the jet stream, typically bring rain storms to California, but National Weather Service meteorologists John Dumas and David Sweet note that so far this year, Los Angeles has seen five percent of its average rainfall, while Burbank has seen even less. In the bottom part of the state, where some areas are enduring a moderate drought, \u0022we\u0026#039;re quite parched,\u0022 Sweet said.As The Verge reports:Storms in the jet stream can get diverted by high-pressure bubbles of warm air. A version of this phenomenon called an \u0022atmospheric ridge\u0022 is to blame for Southern California\u0026#039;s current dry spell. And even bigger one has started forming along the entire West Coast of the U.S. that could shunt rainfall into Canada or Alaska,\u0026nbsp;Swain writes. \u0022We were dry before and now the prospects for rain look even less likely because of the size of this thing,\u0022 Sweet says.This is the same atmospheric phenomenon that squatted over the state for three winters in a row during California\u0026#039;s record-setting, five-year drought. \u0022The real question is how long it persists,\u0022 Swains says. During the drought, these ridges lasted for months at a time—but we don\u0026#039;t know what\u0026#039;s in store for this new one. Even worse news: these atmospheric ridges are getting more common—possibly thanks to human-caused global warming, Swain and his colleagues reported in a 2016 study.\u0022What should make Southern California fearful is that climate change could mean a future of more frequent and more intense wildfires,\u0022 the Los Angeles Times editorial board wrote this week. \u0022Today\u0026#039;s fires will end, and what we do afterward—assessing how to better prepare, and how and whether to rebuild—will influence the damage from the fires next time.\u0022But even getting to that point—where policymakers can consider taking further steps to address climate change and plan for future fires—has proven difficult, as evacuations continue and firefighters find it difficult to contain the fires due to weather conditions—particularly the powerful Santa Ana winds that are expected to remain strong throughout Thursday.