New map shows Bay Area locations with highest risk of ember-driven wildfires

On a new Bay Area wildfire-risk map that gauges the threat of wind-driven embers Lars Guntvedt s neighborhood in the hills above Los Gatos sits in the highest-danger zone Like a multitude of of his of Aldercroft Heights neighbors and plenty of residents around the Bay Area the -year-old school administrator felt confident he had slashed the danger to himself his wife and their wooden home by diligently clearing the surrounding vegetation The ember-risk map Guntveld mentioned made him consider what additional hardening I can do with my house Based on NASA satellite imagery the map shows where vegetation is the bulk likely to produce dangerous fire-spreading embers during high winds and low humidity threatening homes far from main blazes Lars Guntvedt a resident of the Aldercroft Heights neighborhood discusses wildfire jeopardy in the area during an interview on June in the Santa Cruz Mountains south of Los Gatos Calif Dai Sugano Bay Area News Group Current firestorm catastrophes including the deadly razing of Santa Rosa suburb Coffey Park after bits of burning debris from the Tubbs Fire floated over six lanes of Highway and the devastating Los Angeles fires earlier this year have highlighted the role of embers in dramatically speeding and spreading wildfires Embers can send spot fires far ahead of a main blaze igniting yard plants and transporting fire to houses The fire can be down the hill or across the valley and you re going to get embers falling on your property explained Craig Clements director of San Jose State University s Wildfire Interdisciplinary Research Center One or two embers get in the attic and that s what sets off the fire and the house starts burning down The map a collaboration between NASA s Ames Research Center and the fire-protection non-profit Santa Clara County FireSafe Council shows areas where the types and densities of vegetation would be expected to generate embers also known as firebrands that could ride winds to new locations When it comes down it has a very high chance if it s a dense ember very hot in the middle to more or less explode and spew flames out of it which can ignite other vegetation or even a structure announced Christopher Potter an earth scientist at NASA Ames who leads the map project A new map produced by a partnership between NASA's Ames Research Center at Moffett Field and the Santa Clara County FireSafe Council shows zones in the Bay Area deemed the greater part at vulnerability for generating wildfire-spreading embers courtesy of NASA Ames The redder the area on the map the higher the chance it could launch a barrage of dense firebrands Potter disclosed The map comes as context change increases the frequency and severity of wildfires in California four out of five of California s most-destructive wildfires and nine of the largest have occurred since Fire experts say the map provides a valuable new layer of information for Bay Area fire administrators and residents Among the bulk ember-vulnerable communities in the South Bay region fire experts explained are Saratoga Los Gatos Los Altos Hills Morgan Hill Gilroy and in San Jose Almaden and Coyote Valley along with Willow Glen which Potter described as a perfect example of a place where a fire could rip through there burn house after house if it came out of the hills A view of the Aldercroft Heights neighborhood on June in the Santa Cruz Mountains south of Los Gatos Calif Dai Sugano Bay Area News Group I worry about Los Altos and Mountain View burning Potter declared because of all the vegetation that s up there in Los Altos Hills The Oakland and Berkeley hills San Leandro Orinda Moraga and Pleasanton in the East Bay Woodside and Portola Valley on the Peninsula and the Ross valley in Marin County also are vulnerable experts disclosed Bay Area downtowns where concrete dominates are generally considered safe from wildfire but countless of their outskirts and suburbs are not High-risk areas on the ember map are often identified in other maps including Cal Fire s But the new firebrand-focused map shows areas considered engines of wildfire spread that menace surrounding neighborhoods and landscapes During the conditions that generate a lot of embers you re going to get heavy ember casts out to one or two miles reported Michael Wara senior research scholar at Stanford University s Woods Institute for the Climate Jared Lewis manager of environmental planning and natural tools at San Jose Water the utility that owns and manages much of the Los Gatos Creek watershed reported the ember map s higher level of detail and resolution than the Cal Fire maps is already helping the utility identify new areas of pitfall and prioritize where to thin and clear vegetation To produce the map satellite imagery is analyzed to show the landscape by categories of vegetation forest shrub and grasses and how thickly they grow That imagery is combined with material showing which vegetation species tend to produce dense embers that can trip long distances without burning out plus additional mapping by NASA and the U S Department of Agriculture of where plant species grow around the Bay Area Potter announced Multiple plants common in the Bay Area can produce dangerous embers including coyote brush chamise broom eucalyptus manzanita pampas grass acacia bay multiple pines and Douglas fir Potter disclosed The map is intended to guide work to cut fire pitfall through controlled burns fire breaks and thinning and trimming of firebrand-prone trees and other vegetation particularly in locations close to residential and commercial areas where these embers don t have to journey far to cause a conflagration disclosed Seth Schalet CEO of the Santa Clara County FireSafe Council The map also will provide a compelling tool to persuade local administration and private landowners to take on that work or contract with the council to have it done Schalet added Related Articles Opinion California s proposed ban on plants near homes could be dangerous advice How home lenders are impeding Californians from rebuilding fire-torn L A As brush fire races toward SJ homeless encampment residents dig a fire line What s behind the smoke advisory in the Bay Area California lawmakers advocate for increased pay and better protections for incarcerated firefighters Stanford s Wara noted that once large numbers of houses catch fire they re generating plenty of embers all on their own He favors extensive prescribed burns including right around houses The FireSafe Council is working to add layers of information on top of the new map including which areas have the worst routes in and out and which communities like Aldercroft Heights have multiple older homes less resistant to fire Schalet stated He would like to see ember-risk maps statewide NASA Ames is looking at wind patterns during past fires to add another layer to determine for example that not only is this a really bad ember production place but it also routinely gets winds at mph during the dry periods of the year Potter reported Up in Aldercroft Heights Guntvedt s neighbor Garry Howard a -year-old retired electronics entrepreneur keeps grasses and brush cut down to dirt around the wood-sided house he shares with his wife and adult daughter But he disclosed Flying embers my god how do I gauge that It could be nothing It could be catastrophic Garry Howard a resident of the Aldercroft Heights neighborhood discusses wildfire threat in the area during an interview on June in the Santa Cruz Mountains south of Los Gatos Calif Dai Sugano Bay Area News Group