Several large fire complexes continue to burn in Northern California with red flag conditions expected today that may result in extreme fire behavior and additional fire spread as well as the possibility of new fires. Numerous evacuation orders remain in place across the state.
Remnants of Pacific Hurricane Genevieve are expected to bring additional dry thunderstorms to northern California and the northern Great Basin today into tomorrow with additional fire ignitions possible prompting Red Flag Warnings. Numerous evacuations are in place in California with additional evacuations in Colorado and Arizona due to elevated fire activity in those regions.
CalFire estimates that 12,000 lighting strikes occurred during the lightning siege of August 15-17 resulting in over 600 wildfires that have burned an estimated 1.1 million acres. Among the largest of the fire complexes that resulted from the lightning siege are the SCU Complex, the LNU Complex, and the CZU Complex.
The SCU Complex, affecting portions of Santa Clara County, Alameda County, Contra Costa County, San Joaquin County, and Stanislaus County has burned in excess of 347,000 acres and is currently 10 percent contained. Despite the large size of the fire the initial ignition by lighting in relatively remote areas has resulted in the fire damaging or destroying only 24 structures to this point although numerous evacuations remain in effect. Winds today in the region of the SCU Complex are expected to 5 to 10 miles per hour out of the south.
The LNU Complex, affecting portions of Lake County, Napa County, Solano County, Sonoma County, and Yolo County has burned approximately 350,000 acres and is currently 22 percent contained. It is now the 2nd largest fire in California state history. Erratic winds and thunderstorms are expected in the region of the LNU Complex today meaning extreme fire behavior and additional fires are possible in the region. CalFire reports 871 structures have been destroyed by the LNU Complex with an additional 234 structures damaged. Numerous evacuations remain in place as the complex continues to threaten several communities, including Vacaville.
The CZU Complex in Santa Cruz and San Mateo counties has burned approximately 74,000 acres and is 8 percent contained according to CalFire. An estimated 77,000 people are under evacuation orders as fire danger remains elevated today due to the threat of dry lightning and erratic, gusty winds in the region of the complex. CalFire estimated 163 structures have been destroyed by the CZU Complex with an additional 12 structures damaged.
While the Red Flag Warnings issued for California largely expire Monday evening a chance of isolated dry thunderstorms will persist into Tuesday. Following this period of unsettled weather, temperatures in the region of the California fire complexes is expected to return to seasonal normals which will aid in ongoing fire suppression. The Hot-Dry-Windy index, a measure of conditions that are favorable for fire growth which had been above the seasonal 75th percentile for the San Francisco Bay Area the last ten days (including several days above the 95th percentile) is forecast to drop below the 50th percentile late this week indicating conditions will become more averse to rapid fire growth.
Outside of California the Salt Fire, located approximately 70 miles east of Phoenix, Arizona has burned over 20,000 acres and is 20% contained according to the National Wildfire Coordinating Group (NWCG). There are no evacuation orders in place for the Salt Fire several communities are under ‘Ready’ orders to prepare for potential evacuation. Temperatures are expected to be in the high nineties today with erratic and gusty winds possible from thunderstorms that may lead to erratic fire behavior and continued fire growth.
Two fires burning in Larimer County, Colorado, the Cameron Peak Fire, located approximately 45 miles west of Fort Collins, Colorado and the Lewstone Fire have resulted in mandatory evacuations. The Cameron Peak fire has burned over 18,000 acres with and is currently 0 percent contained. The fire, located just to the north of Rocky Mountain National Park has been burning since August 13. The Lewstone Fire, located 15 miles west of Fort Collins, ignited on August 22 and is currently 12 percent contained with an approximate size of 165 acres. Temperatures in the region of both fires today is expected to be in the upper seventies with relative humidities in the mid teens, although there is a chance of dry thunderstorms on Monday that may result in increased fire activity and additional ignitions.
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Official statements from emergency management agencies supersede this update, and should be closely monitored concerning matters of personal safety.