SDG&E, UCLA helped to develop Santa Ana
Wildfire Threat Index
____ The USDA
Forest Service, in collaboration with San Diego Gas & Electric
(SDG&E) and UCLA, Wednesday September 17, 2014 unveiled a new web-based
tool to classify the fire threat potential of a weather phenomenon unique to
Southern California – the powerful, hot, dry Santa Ana winds that can turn a
spark into an inferno.
Ana Wildfire Threat Index, which includes four classification
levels from “Marginal” to “Extreme,” will be used to help fire agencies, other
first-responders and the public determine the appropriate actions to take based
on the likelihood of a catastrophic wildfire fueled by high winds.
“Given the current state of fuel conditions, we have the potential to
see devastating fires this fall should significant Santa Ana winds occur,” said
Forest Service Meteorologist Tom Rolinski. “This tool will directly benefit
fire agencies by allowing us to better anticipate what kinds of resources may
be needed, as well as where and when we could face the greatest challenges.”
Since the 2007 wildfires in San Diego County, SDG&E has been a
partner in enhancing local fire preparedness and has taken major steps to
strengthen its overhead electrical system – changing out wooden power poles for
steel – to make the grid more wind- and fire-resistant. The utility also hired
in-house meteorologists and installed 150 weather stations across its service
area to gather real-time information about the impact of weather on utility
equipment – all to improve situational awareness during emergencies.
SDG&E’s Dave Geier, vice president of electric transmission and
system engineering, considered other ways to leverage this significant amount
of weather data and to share it broadly.
“I asked my team to come up with something similar to the categories to
rate hurricanes that could be used to classify Santa Ana wind events based on
their potential to spread a major fire, which would help us in making
operational decisions to protect our system and our customers,” said Geier.
“The goal was to develop a uniform and recognizable system that also could be
used to alert fire agencies and communities in time to prepare and take
As luck would have it, Rolinski already had been working on a similar
concept and was eager to share ideas and information. Initially, SDG&E’s
meteorologists compiled hourly weather data for the last 30 years in Southern
California – information that was used as a basis for the models that
eventually led to the four-level wildfire threat index. The utility reached out
to regional fire agencies, including the Forest Service and CAL FIRE, along with
universities in Southern California, to partner in the development of the
index. SDG&E also provided funding for state-of-the-art computing hardware
and software to help turn the raw data into a manageable tool
The actual “number crunching” was done by a team from UCLA, led by Dr.
Robert Fovell, Ph.D., chair of the university’s Department of Atmospheric and
Oceanic Sciences, who applauded SDG&E’s weather network for “its
unprecedented station density and uniformity.”
“We not only have a new, deeper understanding of how the San Diego-area
terrain influences weather, especially wind, which is crucial to SDG&E’s
operations, but we also have been able to make improvements in weather modeling
that will benefit forecasters worldwide,” said Dr. Fovell.
The threat index includes four levels of increasingly severe fire
· “Marginal” (yellow) - Upon ignition, fires may grow rapidly.
“Moderate” (orange) - Upon ignition, fires will grow rapidly and will be
difficult to control.
· “High” (red) - Upon ignition, fires will grow very rapidly, will burn intensely, and
will be very difficult to control.
· “Extreme” (purple) - Upon ignition, fires will have explosive growth, will burn very
intensely, and will be uncontrollable.
The National Weather Service (NWS) is the agency that issues a Red Flag
Warning when weather conditions indicate the development of a strong Santa Ana.
Forecasters look at fuel moisture, humidity levels, temperature and topography,
as well as wind speed, to determine whether to declare a Red Flag Warning,
which typically means high fire danger with increased
probability of a quickly spreading vegetation fire in the area within 24 hours.
“This index will help forecasters to quantify a Red Flag Warning and the
public to better understand the risk,” said Roger Pierce, director of the NWS
in San Diego. “We believe this new tool will support and complement our
forecasts and provide even more information to help the public to be better
The Santa Ana Wildfire Threat Index is intended to be used by fire
agencies, emergency responders, the media and the public. The Forest Service
“owns” the tool and is the agency responsible for determining and issuing the
alerts, which can be found on the agency’s website at: www.santaanawildfirethreat.com
“Each of the levels includes recommended ‘calls to action’ that escalate
as the chance of a catastrophic fire becomes more likely,” said Rolinski.
Recommended actions for the public include closely monitoring fire
conditions, making sure cell phones are charged and vehicle gas tanks are full,
as well as reviewing emergency evacuation plans at work and at home and
registering phones to receive reverse-911 warnings for the latest information
about an emergency.
San Diego Gas & Electric
SDG&E is a regulated public utility that provides safe and reliable energy
service to 3.4 million consumers through 1.4 million electric meters and
861,000 natural gas meters in San Diego and southern Orange counties. The
utility’s area spans 4,100 square miles. SDG&E is committed to creating
ways to help customers save energy and money every day. SDG&E is a
subsidiary of Sempra
Energy (NYSE: SRE), a Fortune 500 energy services holding
company based in San Diego. Connect with SDG&E’s Customer Contact Center at
800-411-7343, on Twitter (@SDGE) and Facebook.
UCLA’s Department of Atmospheric & Oceanic
UCLA is California's largest university, with an enrollment of more than
40,000 undergraduate and graduate students. The UCLA College and the
university's 11 professional schools feature renowned faculty and offer 337
degree programs and majors. UCLA is a national and international leader in the
breadth and quality of its academic, research, health care, cultural,
continuing education and athletic programs. Seven alumni and six faculty have
been awarded the Nobel Prize.