Advancing the Understanding of Santa Ana Winds and Wildfires

Advancing the Understanding of Santa Ana Winds and Wildfires

Santa Ana winds have always been a concern for Southern Californians. Under certain conditions, these strong winds can fuel wildfires that threaten homes, property and livestock.

Given the threats associated with Santa Ana conditions, SDG&E has worked to strengthen the electrical system and also better understand the windy conditions and their connection to wildfires. This effort includes building the development of America’s largest utility-owned weather network, a number of regional public safety partnerships, and research.

One key result of this effort is a public safety tool – the Santa Ana Wildfire Threat Index (SAWTI) – that came as the result of a collaborative effort with the U. S. Department of Agriculture/U.S. Forest Service, UCLA. Introduced in 2014, the SAWTI leverages cutting-edge fire science to classify the likelihood of catastrophic wildfires during Santa Ana conditions.

Rating Fire Potential

SAWTI uses supercomputing algorithms to accurately predict vegetation dryness, humidity levels, temperature, and wind speeds that correlate with high fire risk.

SAWTI classifies the conditions into four levels of increasing fire danger:

  • “Marginal” – Upon ignition, fires may grow rapidly.
  • “Moderate” – Upon ignition, fires will grow rapidly and will be difficult to control.
  • “High” – Upon ignition, fires will grow very rapidly, will burn intensely, and will be very difficult to control.
  • “Extreme” – Upon ignition, fires will have explosive growth, will burn very intensely, and will be uncontrollable.

Similar to hurricane-strength categories, the rating system helps the public, first responders and energy company crews plan their response based on the severity of the threat. For example SDG&E may stage crews in a certain area in advance of severe weather so the company is ready to quickly respond to changing conditions that could threaten public safety. Additionally, each rating comes with a recommended action to help the community better prepare for the potential of catastrophic wildfires based on the rating scale.

Learn More

Learn more about the science behind the SAWTI in a recent a scientific paper that was published by the American Meteorological Society Journal of Weather and Forecasting.

SAWTI can be accessed via, or on Twitter (@sawti_forecast), or by downloading the San Diego County’s SD Emergency App for your mobile device.