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Still-raging Thomas Fire proves tough challenge for firefighters

By Arindam Samanta December 12, 2017

Verisk FireLine analysis of the Thomas FireFirefighters made headway over the weekend in containing many of the wildfires that broke out earlier this month, but the massive Thomas Fire continues to rage. Encompassing 230,500 acres, the fire was reported by Cal Fire at only 15 percent contained on Monday (December 11).

Thomas Fire FireLine analysis

Verisk FireLine analysis of the Thomas FireUsing FireLine®—Verisk’s wildfire risk management tool—to analyze risk factors seen within the Thomas Fire’s perimeter, Verisk determined that areas considered to be at high/extreme risk account for more than 96 percent of the total area. This is due to heavy fuels and difficult terrain. The map to the right and chart below show percentages of properties analyzed at extreme, high, and moderate/low/negligible risk.

The Thomas Fire, which started December 4, has destroyed more than 800 structures, damaged more than 180 others, and still threatens some 18,000 structures. The fire has also led to mandatory evacuations from many areas in Ventura County and voluntary evacuations from threatened communities in Santa Barbara County.

Other fires mostly contained

Meanwhile, the Creek, Rye, Skirball and Lilac fires have been mostly contained.

The Creek Fire in Los Angeles County, which started December 5, consumed 15,619 acres, destroyed 60 residential and 63 outbuildings and damaged another 55 residential and 26 outbuildings, according to Cal Fire, which on December 11 reported the fire at 95 percent contained.

Rye and Lilac fires

San Diego County’s Lilac Fire was reported at 80 percent contained . The fire has burned through 4,100 acres. 151 structures have been reported destroyed and another 56 damaged. Meanwhile, the Rye Fire in Los Angeles County, reported at 93 percent contained on December 11, has consumed 6,049 acres. Six structures were reported destroyed and another three damaged.

Skirball Fire

Although significantly smaller, at 422 acres burned, the Skirball Fire broke out as a small brush fire on December 6, later ripping through the high-income neighborhood of Bel-Air. As of December 10, several multimillion dollar homes were reported destroyed and 11 structures damaged. Interstate 405 (a major north-south Southern California highway) was shut down, but has since reopened.


Arindam Samanta, PhD, is director of product management and innovation at Verisk. You can contact Arindam at asamanta@verisk.com