Visualize: Insights that power innovation

Visualize: Insights that power innovation

California, Colorado wildfires show extreme behavior amid heatwave

By Dr. Arindam Samanta, Kaitlyn Perham , Dr. Baijing Cao  |  August 18, 2020

Multiple major wildfires have scorched more than 170,000 acres combined in California and Colorado. Some fires showed extraordinary behavior in their intensity and rate of spread.

Lake, Loyalton, Jones Fires rage in California

The Lake Fire surpassed 19,000 acres as of August 17 after igniting on the afternoon of August 12, according to the California Department of Forestry and Fire Protection (CAL FIRE). Nearly 25 structures were either destroyed or damaged, CAL FIRE said, and over the weekend about 100 homes were evacuated near the community of Lake Hughes, CBS News reported.1 The fire was about 38 percent contained, according to CAL FIRE. More than 2,000 firefighters were at the scene. The cause was unknown.

The Loyalton Fire, burning in portions of Sierra, Plumas, and Lassen counties near the Nevada border, grew to more than 36,000 acres as of August 17 according to InciWeb, an interagency incident information management system. Eleven structures have been destroyed in the fire, which was about 30 percent contained. Mandatory evacuations were in place, KTVN-TV reported.2 The blaze, which may have been caused by lightning, led to the formation of an extremely rare fire tornado, a vortex of smoke, fire, and dirt that can form in a pyrocumulonimbus cloud above a wildfire, CNN reported.3

The Jones Fire ignited August 17 in the South Yube River canyon in Nevada County.  The fire had burned about 550 acres by August 18, and it was at 5 percent containment, according to CAL FIRE. About 1,500 homes were evacuated, KTXL-TV reported.4 The cause of the fire was believed to be lightning, according to KTXL.

Colorado contends with Grizzly Creek, Pine Gulch, Cameron Peak Fires

The Grizzly Creek Fire in Colorado’s Glenwood Canyon grew to more than 25,000 acres on the morning of August 17 after igniting on the afternoon of August 10. Garfield County officials ordered campgrounds near the fire evacuated, and nearby communities were placed on alert. The fire, which according to the Great Basin Incident Management Team was zero percent contained, was burning along Highway 70. The cause was unknown.

The Pine Gulch Fire, about 18 miles north of Grand Junction Colorado, exceeded 86,000 acres on August 17, placing it fourth in terms of largest wildfires in Colorado history, according to KMGH-TV.5 InciWeb reported the fire was 7 percent contained. The cause was believed to be a lightning strike on July 31.

The Cameron Peak Fire had burned more than 12,000 acres as of August 17. with zero containment according to InciWeb. Some mandatory evacuations were in place, KMGH-TV reported.6 The cause was under investigation.

Verisk analysis on active wildfires

FireLine®, Verisk’s wildfire risk management tool, is guiding the analysis of risk factors, including direct exposure to fire damage as well as exposure to smoke and ash damage, seen within and around the perimeters of these fires. The AIR Wildfire Model for the United States, Verisk’s catastrophe risk modeling solution, simulates a 10,000-year stochastic catalog to understand the potential for insured loss each year.

  • Lake Fire (CA): The total area affected by the Lake fire is at risk, and approximately 92 percent of the area is in high to extreme risk categories. The fire in Los Angeles County, which ranks first in the state by number of housing units in the high to extreme wildfire risk categories, according to the 2020 FireLine State Risk Report for California. Loss-causing wildfire events are estimated to occur in Los Angeles County approximately once per year.
  • Loyalton Fire (CA): More than 97 percent of the area affected by the Loyalton Fire is at risk, with more than 77 percent at high to extreme risk. Loss-causing wildfire events are estimated to occur in Sierra County approximately one in every ten years.
  • Jones Fire (CA): The total area affected by the Jones Fire is at risk, with more than 79 percent at high to extreme risk.  The fire is in Nevada county, which ranks fifth in the state by concentration of housing units in the high to extreme risk categories, according to the 2020 FireLine State Risk Reports for California. Loss-causing wildfire events are estimated to occur in Nevada County approximately one in every three years.
  • Grizzly Fire (CO): All of the area affected by the Grizzly Creek fire is at risk, with close to 100 percent at high to extreme risk. Loss-causing wildfire events are estimated to occur in Garfield County approximately one in every five years.
  • Pine Gulch Fire (CO): More than 97 percent of the area affected by the Pine Gulch fire is at risk, and approximately 90 percent of the area is in high to extreme risk categories. Loss-causing wildfire events are estimated to occur in Mesa County approximately one in every five years.
  • Cameron Peak Fire (CO): All of the area affected by the Cameron Peak Fire is at risk, with more than 98 percent at high to extreme risk. Loss-causing wildfire events are estimated to occur in Larimer County approximately one in every five years.

Conditions remain ripe for fire activity

The weather across much of the region affected by the fires was forecast to remain hot, dry, and windy, potentially exacerbating conditions for the fires to grow. Meanwhile, wildland firefighters continue to work under constraints imposed by the COVID-19 pandemic, which in California include scaled base camps and greater use of earth-moving equipment and aircraft in firefighting and monitoring operations.7 For more information on wildfire risk in California and Colorado, please download the 2020 FireLine Risk Reports.

 

  1. “Evacuations remain in place as Lake Fire in California continues to rage,” CBS News, August 15, 2020,
    < https://www.cbsnews.com/news/lake-fire-california-evacuations-lake-hughes/ >, accessed on August 17, 2020.
  2. “Loyalton Fire Burns 36,290+ Acres, 5% Percent Contained, Evacuations in Place,” KTVN-TV, August 17, 2020,
    < https://www.ktvn.com/story/42499009/smoke-coming-from-fire-in-loyalton-california >, accessed on August 17, 2020.
  3. Faith Karimi, “A rare fire tornado is spotted near a blaze in California,” CNN, August 16, 2020, < https://www.cnn.com/2020/08/16/weather/california-fire-tornado-trnd-wx/index.html >, accessed on August 17, 2020.
  4. Doug Johnson, “Jones Fire burning west of Nevada City prompts mandatory evacuations,” KTXL-TV, August 17, 2020,
    < https://fox40.com/news/local-news/jones-fire-burning-west-of-nevada-city-prompts-mandatory-evacuations/ >, accessed on August 18, 2020.
  5. Blair Miller, “Pine Gulch Fire grows to 82,838 acres, with 7% containment and some growth Saturday,” KMGH-TV, August 15, 2020,
    < https://www.thedenverchannel.com/news/wildfire/pine-gulch-fire-grows-to-74-807-acres-with-7-containment-and-some-growth-saturday >, accessed on August 17, 2020.
  6. Blair Miller, “Cameron Peak Fire grows to 12,124 acres, with 0% containment,” KMGH-TV, August 15, 2020,
    < https://www.thedenverchannel.com/news/wildfire/cameron-peak-fire-grows-to-5-424-acres-with-0-containment >, accessed on August 17, 2020.
  7. Paul Vercammen, “California firefighters brace for raging flames and a burgeoning pandemic,” CNN, August 2, 2020,
    < https://www.cnn.com/2020/08/02/us/california-firefighters-covid-pandemic/index.html >, accessed on August 3, 2020.

Dr. Arindam Samanta is director of product management and innovation at Verisk.

Kaitlyn Perham is a geospatial analyst at Verisk.

Dr. Baijing Cao is a wildfire scientist in AIR Worldwide’s research and modeling group.