(TNND) — A warning is in effect for much of Southern California until Wednesday, with further strong winds forecast.

Cal Fire warned of “life-threatening winds and dangerously low humidity” … “creating a significant risk of rapid fire spread.”

Over the past week, wildfires have devastated much of Southern California. At least 24 people were killed, at least 23 others were missing, thousands of buildings were destroyed and a whopping 62 square miles burned.

The Palisades Fire along the Los Angeles County coast was 14% contained as of Monday morning. The inland Eaton fire near Pasadena was 33% contained as of Monday morning.

Another inland fire, the Hurst Fire near Interstate 5 and in the northern part of the San Fernando Valley, was 95% contained.

Dry, strong winds blowing down from the mountains have fueled the spread of these fires.

These are the Santa Ana winds that Southern California experiences several times each year.

“The catastrophe we’re seeing now is largely due to the severity of these winds,” said Jon Keeley, a fire ecologist who works for the U.S. Geological Survey in California.

This time, Santa Ana winds were about twice as strong as normal. And they make for a dangerous combination with dry conditions where any spark can quickly lead to a raging conflagration.

Keeley said winds in Santa Ana typically blow around 30-40 miles per hour.

This time there were winds between 70 and 100 miles per hour in the Los Angeles area, he said.

“These are really severe wind events in Santa Ana,” Keeley said.

Santa Ana winds typically arrive in fall and early winter.

Keeley said they can last anywhere from a few days to several weeks.

The strong winds are the result of a high pressure cell developing east of California, mostly in the Great Basin, and a low pressure cell, typically offshore.

And the Santa Ana winds flow west toward the California coast.

Keeley said Southern California is also experiencing a long drought.

“Normally, rainfall occurs from fall to winter,” he said. “This year we have had almost no rain in the fall and so far in the winter. And so our normal six-month drought is now like a nine-month drought. So it’s very dry, much drier than usual.”

Drought and strong winds alone do not cause destructive forest fires.

There must be some kind of ignition.

While the causes of the current fires are being investigated, Keeley said there is a good chance that power line failures may have played a role.

“Winds of 70 to 100 miles per hour can bring down power lines or cause them to arc and emit sparks,” he said.

Power line failures pose a growing wildfire risk in California.

Keeley said five times more land has burned in the last 20 years than in the previous 20 years due to power line incidents during the Santa Ana winds.

More people now live near natural areas and the power grid has grown with them, he said.

California has added about 6 million people this century.

“So we have a lot more people, and they’re being pushed further and further into the wilderness-urban interface,” Keeley said. “And that doesn’t just mean more people are at risk because they’re closer to the wilderness where these fires originate. But they also involve power lines, which increase the likelihood that ignition will cause a fire.”

The effects of population growth are important to consider, he said, because “there are many reports that suggest this is the result of climate change.” I don’t dispute global warming at all. It happens. But all three of these events, the long drought and the high winds and ignitions due to power line failures, we have seen over and over again over the last 100 years.”

Of course, Santa Ana winds aren’t new either.

And Keeley said their frequency doesn’t change.

But their timing shifts slightly. Looking at the last 70 years of data, he found that there are now fewer Santa Ana wind events in September and more in December and January.

This means the likelihood of forest fires is higher in winter.

What, if anything, can be done to prevent a repeat of the disaster that struck the LA area this week?

Keeley said we can’t stop the strong Santa Ana winds.

There is no magic solution to stop droughts.

“The only thing we can do, undoubtedly, is to work more aggressively on fire prevention,” he said.

Utilities are working on it, Keeley said.

That means better maintenance of the power lines and the removal of fuels – trees and the like – that could catch fire around the power lines.

And sometimes it can mean shutting down parts of the power grid to reduce the risk of fire in times of high danger.