Low Winds Kept California Wildfire Loss Low, Says AIR

NU Online News Service, Sept. 23, 9:28 a.m. EDT

The California wildfire outside Los Angeles, which threatened 12,000 homes, burned only 89 residences thanks to an absence of strong winds, AIR Worldwide, a catastrophe modeling firm said.

Boston-based AIR said the commercial and residential exposure value of the communities next to the southwestern perimeter of the Station Fire totals $17 billion according to the company's industry exposure database.

Had Santa Ana winds pushed the fire into these suburban neighborhoods, losses likely would have been catastrophic--comparable at least to the record Oakland Hills Fire, said AIR. The suspected arson fire is now almost totally contained after more than three weeks of persistent firefighting efforts.

The Station Fire, which began on Aug. 26 near a U.S. Forestry Service Ranger Station in the Angeles National Forest, to date has consumed over 250 square miles, making it the 10th largest blaze in California since 1933, AIR said.

The blaze, AIR noted, is believed to have been deliberately set and officials continue to search for those responsible.

Tomas Girnius, senior scientist at AIR Worldwide said, "The principal mitigating circumstance that prevented the Station Fire from destroying more homes was the moderate winds."

"Hourly reported sustained wind speeds near the fire rarely exceeded 10 mph. Although there were a number of periods when wind gusts exceeded 20 mph and even 30 mph, and these occurrences set back firefighting efforts and delayed the ultimate containment and control of the fire, they were too infrequent to allow it to run completely out of control," he explained.

Mr. Girnius said had the infamous Santa Ana winds been present, the situation could have been far different. "Typically beginning in autumn, these hot and dry winds originate in the desert and sweep through southern California toward the coastline."

He noted that the 1991 the Oakland Hills Fire, the costliest in U.S. history with insured losses between $3billion and $3.5 billion in today's dollars, "was likewise fanned by Santa Ana-type winds."

The steep and rugged terrain, inaccessible by ground vehicles in many places, made Station Fire containment efforts very difficult said Mr. Girnius. "There was no precipitation during the fire and fuel moisture readings were as low as 4 and 5 percent on some days, and only occasionally greater than 10 percent. In the absence of high winds, the very rapid spread of the fire can be attributed to the extremely dry fuels.