Damage caused to a vehicle that was engulfed by the Woolsey Wildfire just outside of Malibu Creek Park, CA. Photo Credit: Jake Di Giovanni.
DISCUSSION: As Californians continue their recovery efforts from the recent Camp and Woolsey wildfires, many questions have been raised over the unprecedented intensity of these fires and what it means for the future of several California communities. And while they are nothing new to the region, the two most recent events have been regarded as being some of the worst wildfires in state history. Much like tornadoes and hurricanes, these natural disasters can instantly threaten any and all future development and projects for towns and villages.
To understand what makes these wildfires a unique challenge for California every fire season, it is equally important to understand the ingredients that are required for all fires: heat and fuel. Rapid, sudden heat transfer on a dry, combustible surface can lead to a spark via anything from natural phenomena, such as lightning strikes, to human activities. Once a flame is produced, it will grow and shrink depending on the amount of fuel that is available; sources of fuel range from dry grasses and shrubs to entire forests and, of course, flammable structures. If left unchecked, an uncontrolled fire with sufficient enough fuel will take on a life its own, becoming a wildfire. In order for wildfires to be able to continue their expansion, they must have an untapped access to sources of fuel. As such, a wildfire’s greatest friend is the wind; if surface and near-surface winds are not strong enough to blow the embers of a wildfire into dry, unburned parcels of land, then they will simply land on smoldering remains and the wildfire will consume itself.
This is where the infamous Santa Ana winds become a critical component for extreme wildfires. As katabatic winds, they occur when a dense, high-elevation air mass travels down to lower elevations via gravity. During the fall, synoptic-scale highs tend to develop over the Mojave Desert, and produce a clockwise flow over most of Southern California. As cool, dry air parcels travel downslope of the San Fernando and San Gabriel Mountains and into the LA Basin, they gain momentum and heat up, permeating over the urban and natural barriers of Southern California until they reach the coastline. As such, these hot, dry, and fast winds help to fan otherwise small brush/grass fires, turning them into massive wildfires like the ones that were witnessed this year. It should also be noted that katabatic winds also develop in a similar fashion in northern California and are referred to as the Diablo winds.
The synoptic-scale mechanisms involved in producing the Santa Ana winds. Photo Credit: Joseph Serna, LA Times.
It’s for these reasons that fire season is such a dangerous time for those living downwind of both the Santa Ana winds in southern California and the equivalent winds in Northern California. When these katabatic winds are at their strongest, the smoke from these wildfires can travel well-beyond their sources and deteriorate air quality across vast distances. Moreover, embers from wildfires are transported through the air, flying across entire neighborhoods and physical boundaries, before settling on new and potentially flammable surfaces. As ABC reporter Morgan Windsor wrote in his article on the two wildfires, the Woolsey wildfire eventually crossed the 101, devastating several upscale towns on the other side of the freeway, including Malibu, CA, and Calabasas, CA. Uncontrolled wildfires can travel at up to 14-15mph, meaning that those who are in their immediate paths can physically see the landscape combust as before their eyes. Unfortunately, this was exactly what happened to residents in Paradise, CA, which was completely decimated and became the deadliest wildfire in California history, with 83 people pronounced dead at the time of this publication.
The mechanics behind the Santa Ana Winds in Southern California. Photo Credit: Joseph Serena, LA Times.
With cleanup efforts currently underway all over the state, many questions have once again been raised regarding the risks that wildfires pose to vulnerable communities that are already dealing with a struggling housing market. As writer for the LA Times Liam Dillon recently wrote in her piece on the California housing crisis, thousands of homes have been destroyed this year alone due to wildfires, some of which were caused by human activity. On top of that, the state's depleted housing stock has only worsened the crisis, and could pose further challenges for the development of areas that are located in at-risk areas. As such, these communities may have to start to consider increasing fire awareness and safety in order to limit any future wildfires from reaching the same levels of destruction as what has been seen this year. Indeed, the state of California will soon need to address these economic issues head-on in order to ensure that recovery efforts can continue smoothly and that homeowners in communities like Paradise, CA, are as informed as possible when it comes to wildfire safety.
Unfortunately for California, these natural disasters will never go away, as they are as integral to the climate of the state as tornadoes are to Tornado Alley, or as hurricanes are to the Gulf Coast. Thankfully, local fire stations, emergency services, and forest management will continue working together to handle these sorts of emergencies. As for the residents of the state begin returning to their lives, the best thing they can is to become more knowledge about wildfires and ensure that they do their part in preventing unintentional, man-made burns in the future.
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© 2018 Meteorologist Gerardo Diaz Jr.