What Caused Maui’s Devastating Wildfires?

Dry conditions and strong winds set the stage for the disastrous wildfires that tore through the historic town of Lahaina and other areas of Hawaii

Hospitals on Maui are overwhelmed with patients suffering from burns and smoke inhalation as wildfires rage uncontrolled on the famously beautiful Hawaiian island. Evacuation orders are in place in several areas of the island, and a few people even fled into the ocean to avoid encroaching flames.

The devastating Maui fires, along with some on Hawaii’s Big Island, are the product of a confluence of weather conditions—namely, strong winds, dry vegetation and low humidity—says Robert Bohlin, a meteorologist at the National Weather Service’s (NWS’s) office in Honolulu.

The stage was set by drought conditions across various parts of the state’s islands, especially Maui. “This is the time of year when we start to dry out,” Bohlin says. That typical dryness has been exacerbated by weaker-than-normal trade winds that have kept rain away, according to the U.S. Drought Monitor. Drought dries out grasses and other vegetation, making them more likely to ignite in a wildfire.

Two other factors have been a large atmospheric pattern that features a strong high-pressure area to the north of the islands and a strong low-pressure area—in the form of Hurricane Dora—to the south. Wind tends to flow from high-pressure areas to low-pressure ones, and the stronger the pressure difference, the faster the winds. “We’re in that sweet spot between that very strong high and that very strong low,” Bohlin says. And the islands’ rugged terrain can sometimes funnel those winds and create stronger gusts. The NWS had warned of winds of 30 to 45 miles per hour, with gusts up to 60 mph. 

Such strong winds can quickly spread flames. “The fire can be a mile or more from your house, but in a minute or two, it can be at your house,” said Maui County’s fire assistant chief Jeff Giesea in a recent press release from the county.

The large atmospheric patterns “also brought in some really dry air,” Bohlin says, which promotes fire growth as well.

All of these conditions make it very difficult for firefighters to beat back the flames, which can spread faster and more unpredictably. Firefighting aircraft have been unable to fly because of the high winds, according to news reports.

The spreading flames have destroyed businesses on the major tourist strip of Front Street in the town of Lahaina on the western side of Maui. Parts of this side of the island have been cut off from communication, and 911 services are not available there, according to the county government.

Thousands of people are also without power. The National Guard has been deployed, and Lieutenant Governor Sylvia Luke has asked the White House to declare a federal emergency.

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