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2023 Hawaii wildfires

Natural disasters in the USA

  • 33 min read
  • 6 chapters
The Coast Guard, along with federal, state, and local partners continue to respond following the Lahaina wildfires in Maui, HI August 9, 2023. A total of 17 lives were saved from the water and 40 surv
Petty Officer 3rd Class David Graham · Public domain

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Through High-pressure area, State of emergency and Invasive species

An emergency declaration was signed on August 8, authorizing several actions, including activation of the Hawaii National Guard, appropriate actions by the director of the Hawaii Emergency Management Agency and the Administrator of Emergency Management, and the expenditure of state general revenue funds for relief of conditions created by the fires. By August 9, the state government of Hawaii issued a state of emergency for the entirety of the state. On August 10, U.S. President Joe Biden issued a federal major disaster declaration.

For the Lahaina fire alone, the Pacific Disaster Center (PDC) and the Federal Emergency Management Agency (FEMA) estimated that over 2,200 buildings had been destroyed, overwhelmingly residential and including many historic landmarks in Lahaina. The damage caused by the fire has been estimated at nearly $6 billion. In September 2023, the United States Department of Commerce published the official damage total of the wildfires as $5.5 billion (2023 USD).

Background

Wildfire risk

The typical area burned by wildfires in Hawaii has increased in recent decades, almost quadrupling. Experts have blamed the increase on the spread of nonnative vegetation and hotter, drier weather due to climate change.

During the 2010s and early 2020s, Clay Trauernicht, a botanist and fire scientist at the University of Hawaiʻi at Mānoa, and several other experts warned that the decline of agriculture in Hawaii meant that large areas of formerly productive land were left unmanaged; nonnative invasive species like guinea grass were spreading rapidly and increasing the risk of large wildfires. The state government failed to provide incentives or impose mandates to keep land clear of grass or require all structure owners to maintain defensible space, a standard rule in fire-prone states like California. The shrinking of the agricultural workforce reduced overall firefighting capacity; those workers had traditionally suppressed fires on the land they cared for, and were so effective that sometimes the counties called them for help. In 2022, Trauernicht suggested that Hawaii follow Europe's example by subsidizing agriculture as a public good as a form of fire risk reduction. In 2023, UH Manoa biogeography professor Camilo Mora estimated the cost of land restoration to mitigate wildfire risk at about $1 billion. Despite these calls to action, the Hawaii State Legislature was unable to make much progress; a 2022 bill to spend just $1.5 million on additional fire risk reduction measures died in a legislative committee.

Around the time the fires occurred, twenty percent of the county of Maui was experiencing moderate drought (level 1 of 4), and sixteen percent was under severe drought conditions (level 2 of 4). A decrease in rainfall consistent with the predicted impacts of climate change had also been recorded in the Hawaiian Islands, according to the U.S. National Climate Assessment. In the decades leading up to the fire, overdevelopment practices led to further water management challenges that reduced the availability of water for firefighting and exacerbated drought conditions.

In June 2014, the Hawaii Wildfire Management Organization, a nonprofit organization, prepared a Western Maui Community Wildfire Protection Plan which warned that most of the Lahaina area was at extremely high risk for burning.

In Maui County's 2020 Hazard Mitigation Plan, the county identified Lahaina, the most heavily impacted community in the August fires, as lying within a high risk zone for wildfire.

In its monthly seasonal outlook on August 1, 2023, the National Interagency Fire Center (NIFC) forecast "above normal" potential for significant wildland fires for Hawaii in August, concentrated on the islands' leeward sides. In addition to noting plentiful vegetation growth from the previous wet season and the expanding drought, the NIFC mentioned that "tropical cyclones can also bring windy and dry conditions depending on how they approach the island chain and can exacerbate fire growth potential".

Long term assessments gravely underestimated the vulnerability of the islands to deadly wildfires. A year prior, the State of Hawaii Comprehensive Emergency Management Plan Report detailed wildfire risks as one of the lowest threats for the state. A 2021 Maui County assessment acknowledged the spike of wildfires in the state, but described funds as "inadequate" and heavily criticized the county fire department's strategic plan, claiming it said "nothing about what can and should be done to prevent fires".

Weather factors

In early August 2023, a high-pressure system remained north of the Hawaiian Islands. This formed strong surface pressure north of the islands, and also sustained stabilization across the region, creating warm and sunny conditions. Concurrently, Hurricane Dora began to intensify to Category 4 strength, which helped create a large pressure difference between the high-pressure area and the low-pressure cyclone. This pressure difference aided in already significant trade winds moving southwest, and formed strong gradient winds over the islands. (A similar phenomenon occurred during the October 2017 Portugal wildfires during the passage of Hurricane Ophelia.) The exact significance of Hurricane Dora and how it impacted the fires remains somewhat unclear. Meteorologists noted that the storm's center remained more than 700 miles (1,100 km) from the islands and relatively small in size; however it also remained "remarkably potent for a long time", logging more hours as a Category 4 hurricane than any other storm in the Pacific for over 50 years. Philippe Papin, a hurricane specialist with the National Hurricane Center, argued that Hurricane Dora played only a minor role in "enhancing low-level flow over Maui at fire initiation time."

By August 6, the National Weather Service identified a region of very dry air arriving from the East Pacific, greatly inhibiting the potential for rainfall. A prominent descending capping inversion forced even more stabilization of the atmosphere, which led to enhanced wind gusts and very dry conditions between August 7 and 8. As the day progressed, deep layer ridging combined with the existing pressure gradient created very strong wind gusts and caused humidity levels to be well below normal. The aforementioned cap was expected to only strengthen acceleration of wind due to terrain features near the islands.

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