Wildfire Warning Signs Flashed on Maui Months Ago, Gro’s Fire Weather Index Shows

A perfect storm of low humidity, drought, and high winds led to the wildfires that tore across Maui, Hawaii, last week, leaving nearly 100 confirmed dead so far, displacing thousands of residents, and decimating the historic town of Lahaina. While the ignition source has not yet been identified, the event highlights the crucial role that technology can play in predicting and managing such disasters to, at the very least, avoid the death of residents, and to minimize potential damage.

Gro’s fire risk and management model, Gro Climate Indicator (GCI): Fire Weather Index, is designed to assess and analyze on a daily basis factors that contribute to the likelihood and behavior of wildfires at a global scale. The index uses critical weather variables — including temperature, humidity, wind, and fuel moisture content — to provide insights into the possible ignition, spread, and intensity of fires, with the aim of enhancing fire-management strategies at the district, province, and national levels globally.

Gro’s model indicates that Maui had been experiencing conditions conducive to wildfires for months before the ignition. The chart below shows how 2023 FWI values (red line) for Maui have been well above historical averages since June.

The FWI detects decreases in rainfall and relative humidity paired with increasing surface winds. This combination of variables can provide an early warning for regions in danger to take preventative action to guard against wildfires.

Wildfire intensity is determined by the conditions leading up to the ignition, not just on the day of the event. In Maui, months of hot and dry weather have desiccated live vegetation and dead plant matter, creating prime fuel sources for wildfire. Hawaii has also been battered by strong, dry winds from the eastern Pacific Ocean, which intensified as Hurricane Dora passed hundreds of miles south of the islands.

Areas in red in the time-lapse image below show areas where fire weather conditions have been especially high in the period from May 1 to August 5, 2023. Note that much of California and other parts of the West Coast are also at heightened risk.

Gro Intelligence's GCI: Fire Weather Index aims to provide stakeholders with valuable insights to effectively allocate resources and mitigate the devastating impact of wildfires. These proactive measures are essential for safeguarding lives and property.