How the LAFD determines wildfire danger in Los Angeles

October 30, 2023
Los Angeles Fire Departmnet

In an effort to strategically allocate resources during times of high wildfire danger in Los Angeles, the Los Angeles Fire Department (LAFD) heavily relies on a systematic approach, according to a report from LAFD Spokesperson Brian Humphrey.

Science-based approach to wildfire danger

At the heart of this strategy is science. LAFD employs the Burning Index (BI): “Your LAFD utilizes a Burning Index (BI) to determine exactly when and where apparatus and personnel should be pre-deployed.”

The process begins with: “dead vegetation fuel moisture readings are carefully taken in the early afternoon at Fire Station 108 on Mulholland Drive near Coldwater Canyon, and communicated to LAFD Valley Bureau Headquarters.”

Role of meteorologists and historical data

Another significant contribution comes from federal meteorologists: “a group of federal meteorologists at the Southern California Geographic Area Coordination Center (OSCC) in Riverside, California provide a fire weather forecast consisting of a predicted high temperature, low relative humidity, wind speed and direction for the next day.”

Moreover, “historical data (high/low temperature, high/low relative humidity and hours of rainfall in the last 24 hours) is mixed into the brew.”

This gathered data is input into the National Fire Danger Rating System (NFDRS), resulting in the BI. The BI levels are as follows:

  • BI 0 to 37 = Low
  • BI 38 to 47 = Moderate
  • BI 48 to 110 = High
  • BI 111 to 161 = Very High
  • BI 162 and above = Extreme

Practical implications of the BI

LAFD takes the BI’s guidance seriously: “On days of Extreme Fire Danger, your Los Angeles Fire Department may pre-deploy resources at select Neighborhood Fire Stations in-and-near areas prone to wildfire.”

However, the LAFD remains adaptive, with Valley Bureau staff conducting: “real-time weather surveys, monitor Remote Automated Weather Stations (RAWS) in and near the City of Los Angeles and consult the National Weather Service (NWS) to stay abreast of fire weather conditions and forecasts.”

Decoding weather reports for residents

Residents are reminded: “Please remember that radio and television weather reports are broadcast to a wider community than the City of Los Angeles, and the information they share on ‘Red Flag Warnings’, for instance, may not apply to the areas served by your LAFD.”

Furthermore, LAFD has its unique terminology: “LAFD uses the specific term ‘Red Flag Alert’ to indicate forecast or existing ‘Red Flag’ conditions inside the City of Los Angeles.”

In specific conditions, when the wind speed exceeds 25 miles per hour and humidity drops below 15%, a “Red Flag Alert” is activated.

This alert, history shows, signifies the presence of factors, including “strong winds, low humidity and warm temperatures”, that elevate the risk for rapid fire spread.

For up-to-date information on parking restrictions during “Red Flag Alert” conditions, residents can visit: LAFD.ORG/RedFlag.

FSJA Comment

In a region as vast and variable as Los Angeles, understanding and predicting wildfire dangers is vital for both residents and the emergency services dedicated to protecting them.

The systematic approach detailed by LAFD Spokesperson Brian Humphrey sheds light on the intricate methodologies in place.

This comprehensive, multi-tiered system ensures that the City of Los Angeles receives the most accurate information possible, allowing for the strategic allocation of resources and timely alerts for the community.

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