Weeks without rain, above-normal temperatures and loads of dry fuels littering the ground have paved the way for fire danger warnings.

It’s not a familiar fall forecast in the northeastern United States, but drought conditions and human-caused fires have sparked unusual fire activity.

Wildfires in New York, New Jersey and neighboring states, as well as wind-driven fires in California, are of concern to scientists and wildland managers across the country.

“We’re used to long dry periods here in the Southwest because of our seasonality and precipitation,” said Michael Crimmins, a climatologist at the University of Arizona.

“But when it doesn’t rain in the eastern part of the country, accustomed to receiving rain every other day, it can quickly slide into drought conditions.”

A series of wildfires have broken out across the Northeast, from a small fire in Prospect Park in Brooklyn to the 5,000-acre Jennings Creek Fire along the New York-New York border. Jersey, a fire that killed an 18-year-old park ranger.

On the other side of the country, the Mountain Fire in Ventura County, California, destroyed nearly 250 structures and burned more than 20,000 acres this week.

After a record fall characterized by extreme heat and drought conditions, fire risk persists beyond the traditional peaks of the wildfire season.

Here’s what’s fueling fall fires, what the current fire risk is in Arizona, and how climate change is contributing to a longer fire season:

What Fuels Fall Fires?

This year, summer heat and dry spells continued into the fall across much of the United States, setting the stage for late-season wildfires on both coasts.

“October was one of the driest on record in the continental United States, and on top of that was the heat,” Crimmins said. “The heat gripped a large part of the country during this period. »

With dry conditions and above-average temperatures, Crimmins said evapotranspiration — when water is transferred from plants and soil to the atmosphere — increases and dries the land.

Authorities issued red flag fire warnings from New Jersey to Massachusetts, after weeks with minimal rain in the Northeast.

Connecticut has reported more than 80 wildfires and is under a Level 2 drought advisory. Massachusetts saw a 1,200% increase in fire activity in October, reporting more than 200 wildfires. forest compared to the average of 15 fires.

The Jennings Creek Fire in New York and New Jersey has not been contained and authorities fear high winds could spread it.

While fall can bring cooler temperatures, it can also call for more fuel: leaves.

“The leaves had all fallen off the trees and they dropped a bunch of fuel on the ground,” Crimmins said. “I’ve seen photos of firefighters using leaf blowers as part of their firefighting tools, blowing leaves to clear fire breaks because that’s what carries objects to the ground.”

Wildfires are not uncommon in the Northeast, but this fall has seen a sharp increase in fires alongside rapid growth.

Fires in California are more common, but activity at this time of year is still a cause for concern due to the Santa Ana winds, a seasonal wind pattern that occurs primarily in the fall, bringing extremely strong, dry downslope winds and lower relative humidity. across Southern California. The winds blow from the desert and head towards the coast.

“Any human fires that happen in front of that wind are going to result in these large destructive fires that happen in Southern California,” Crimmins said. “Like us, Southern California had a very wet winter and they’re growing all kinds of things ready to burn.”

Southern California’s wildfire season continues later in the year than in other parts of the country, largely because of winds that can turn sparks into inferno.

What is the risk of fire in Arizona?

Fire activity in the Southwest typically peaks in April, May and June, but to decrease fire activity the region relies on moisture from monsoon precipitation. This year’s monsoon was sporadic and the seventh driest on record.

“It’s all humidity,” said Andrew Mandell, a Tonto National Forest fire officer, citing the forest’s dry conditions. “We’ve had a little bit of that and we have a little moisture possible in the short-term forecast.”

As snow begins to blanket Arizona’s high elevations, there is still a risk of fires at lower elevations.

Mandell said it was an “extremely busy” fire season for the forest, with 195 fires burning 130,000 acres. Even if the risk of fire has decreased, they are still possible on the Tonto. Tonto Forest covers low-lying wilderness, where snow is rare.

“We continue to have fires, we had an 80-acre fire (Tuesday) in the Mesa Ranger District,” he said. “They don’t get out of control, but we still see the fires get a little bit bigger in November, which becomes more common with a longer fire season than we see on the Tonto.”

Extreme hazard fire restrictions were not lifted across the entire Tonto National Forest until early September, and fire crews began prescribed burn operations late due to inadequate conditions.

They began prescribed burning operations this week in the Globe Ranger District.

But as the risk decreases, that doesn’t mean fires won’t start.

“Whether or not we have fire restrictions, we certainly want everyone to enjoy public lands responsibly,” Mandell said. “Just be mindful and responsible when it comes to fires in recreational activities because we certainly don’t want unwanted fires breaking out on the landscape.” »

How is climate change taken into account?

Although wildfires are a natural phenomenon that can benefit ecosystems in moderation, scientists are concerned about longer fire seasons and large-scale wildfires. They believe climate change plays a role in making fires worse.

“Climate change is part of everything, but it’s not the root cause of anything,” Crimmins said. “It’s kind of like the background condition.”

It’s still unclear exactly how a warming atmosphere affects certain weather events such as Santa Ana winds or fall precipitation, but scientists do know that higher temperatures dry out vegetation more quickly, creating dangerous fuels.

This year is shaping up to be the hottest on record, and with much of the country experiencing drought conditions, the fire season continues to lengthen.

“We’ve seen fire seasons get longer over time, since the beginning of my career – and I think I’m at 30 years now – they are significantly longer than they used to be ” Mandell said.

Fire activity in the Northeast is something scientists and fire crews should pay attention to, according to Crimmins.

“It’s a strange confluence of things, and while it’s not unprecedented, it’s just so unusual to have long periods of drought on top of increasing temperatures. It just increases the risk of fire,” Crimmins said. “It’s weird, and we have to be careful about this kind of thing.”

Hayleigh Evans writes about severe weather and related topics for The Arizona Republic and azcentral.com. Send him story tips to [email protected].

This article was originally published on Arizona Republic: Dry fall fuels coast-to-coast wildfires, raising concerns in Arizona