What Caused Maui’s Deadly Wildfires? How dry conditions and Hurricane Dora set the stage for an inferno that swept through paradise

Hawaii’s wildfires destroyed a historic town and killed dozens of people after a hurricane hundreds of miles from the islands combined with dry conditions to spread the flames at an “unprecedented” rate.

At least 36 people have been killed, many injured and hundreds are feared missing as hell continues to burn on the paradise island of Kaui. The historic city of Lahaina has been totally destroyed.

Wildfires began to spread rapidly on Tuesday and were soon spun out of control by wind gusts of up to 80 mph brought on by Hurricane Dora. The Category 4 hurricane passed about 500 miles south of Hawaii.

Low humidity and prolonged hot temperatures turned grasslands on Kaui into a “tinder box” that allowed the flames to spread incredibly quickly.

Those combined factors also made it impossible to control the fires.

An aerial view of destroyed buildings as the wildfire burns in the historic town of Lahaina, Hawaii on August 9, 2023.

The hall of the historic Waiola Church in Lahaina and the nearby Lahaina Hongwanji Mission go up in flames along Wainee Street on Tuesday, August 8, 2023

Lahaina Mayor Richard Bissen Jr. said the situation is “unprecedented.” Thousands of people have been evacuated from the city, where nearly 300 buildings have been confirmed destroyed, and the death toll is likely to rise.

Kelsey Copes-Gerbitz, a postdoctoral researcher in the forestry faculty at the University of British Columbia, said conditions have led to “unpredictable or unforeseen combinations that we are now seeing that are fueling this extreme fire weather.”

“What these … catastrophic wildfire disasters reveal is that nowhere is immune to the problem,” Copes-Gerbitz said.

Meteorologists say large differences in air pressure caused unusually strong trade winds to fuel the destructive flames.

Trade winds are a normal feature of Hawaii’s climate. They are caused when air moves from the high-pressure system pressure north of Hawaii — known as the North Pacific High — to the low-pressure area at the equator, in the south of the state.

CH47 Chinook helicopters of the Hawaii Army National Guard deliver water buckets from the air on the island of Maui to help fight wildfires in Maui, Hawaii, August 9, 2023

A man sits in a chair amid the utter devastation of the island. Joe Biden called for federal aid to reach Hawaii on Wednesday night

Smoke rises near Lahaina as wildfires triggered by high winds destroy much of the historic city of Lahaina

Lahaina nearly wiped off the map after 271 buildings burned to the ground in fierce wildfires

But Hurricane Dora, which moved south of the islands this week, is worsening the low-pressure system and increasing the air pressure differential to create “unusually strong trade winds,” said Genki Kino, a meteorologist with the National Weather Service office in Honolulu. .

Hawaii’s state climatologist Pao-Shin Chu said he was taken aback by the impact Dora had from about 500 miles away.

“Hurricane Dora is a long way from Hawaii, but you still have this fire here. So this is something we didn’t expect to see,” he said.

Strong winds, combined with low humidity and an abundance of dry vegetation that burns easily, can increase the danger of wildfires, even on a tropical island like Maui.

“When you have all of these conditions at the same time, it’s often what the National Weather Service calls ‘red flag conditions,'” said Erica Fleishman, director of the Oregon Climate Change Research Institute at Oregon State University.

People gather while waiting for flights at the Kahului Airport Wednesday, August 9, 2023 in Hawaii. Several thousand Hawaii residents rushed to flee homes on Maui as the Lahaina fire swept across the island

People gather at Kahului Airport awaiting flights on Wednesday, August 9, 2023

Passengers try to sleep on the floor of the airport terminal as they wait for delayed and canceled off-island flights as thousands of passengers were stranded at Kahului Airport (OGG) in the aftermath of wildfires

She said higher temperatures due to climate change are also “increasing dryness of vegetation,” contributing to wildfires.

Fleishman added, “There is an increasing trend in hurricane intensity worldwide, in part because warm air holds more water.”

Clay Trauernicht, a fire scientist at the University of Hawaii, said the wet season can encourage plants like guinea pig grass, a non-native, invasive species found in parts of Maui, to grow and reach up as fast as six inches a day. up to 3 meters high.

When it dries out, it creates a tinderbox ripe for wildfires, Trauernicht said, adding, “These grasslands accumulate fuels very quickly.

“In warmer and drier conditions, with variable rainfall, this will only exacerbate the problem.”