Oklahoma Wildfires Are Becoming An Ugly Pattern

A wildfire explodes viciously as it encounters parched eastern redcedar durimg
devastating Oklahoma wildfires this past week.
Photo by Alan Broerse. 

Oklahoma never used to be famous for earthquakes and wildfires.

That's California's job.

People associate Oklahoma with tornadoes, and they still happen there very frequently. (That said there has so far been a real dearth of Oklahoma tornadoes this year.)

But earthquakes, and now wildfires are very Oklahoman, and it's pretty easy to blame the fossil fuel industry, which is such a large part of the Oklahoma economy. Especially the earthquakes, though the wildfires might just be tangentally related to the fossil fuel industry.

Oklahoma is now the most earthquake prone state in the United States. Most of them are caused by wastewater disposal. Oil is extracted from the ground, but a lot of is mixed with briny water. The water needs to be disposed of, so it's injected well below the earth's surface, below the aquafers so drinking water won't be contaminated. This causes earthquakes.

But this is a weather and climate blog, and we're really here to talk about wildfires. This is the third year in a row Oklahoma has had devastating wildfires, and this year appears to be the worst.

At least two people have died in the wildfires over the past week or so and dozens of homes have been destroyed.  One fire in Oklahoma had burned 440 square miles and was only 15 percent contained as of Thursday morning.

There was at least some temporary relief Friday and Friday night for Oklahoma: Numerous showers and thunderstorms dumped some fairly decent rains on the worst of the fire zone. And some more showers are in the forecast this week. But the damage is really done. And extreme.

So what's the deal with all these Oklahoma wildfires over the past three years?

Bob Henson in his Category 6 blog has a great overview of what's been happening.

In the late winter and early spring, strong, dry winds often blow in from the west. The winds warm up and often become hot once they get down the slopes of the eastern Rockies, so it's basically a blowtorch by the time you get to Oklahoma.

Relative humidities can often drop into the single digits during these episodes and winds can gust to between 40 and 60 mph, or even more in some instances.

These hot, dry early spring winds aren't new to Oklahoma, and they have always spawned wildfires.

In recent years, though, droughts have gotten extraordinarily bad, particularly in western Oklahoma and northwestern Texas.

Mixed in with these droughts have been extraordinarily wet periods, which encourages vegetation to grow vigorously. For instance, 2015 was a record wet year, and it was warm. Things grew well into the late fall, so there's lots of extra grasses, shrubs and whatnot out there.

Then there was a flash drought in early 2016, and a lot of that extra vegetation went up in flames. This boom/bust cycle of heavy rain and drought has continued. This feast and famine regime could be related to climate change, so there's your fossil fuel link to this wildfire story.

Then there's shrubby tree called the eastern redcedar. It's a tree-sized juniper that you commonly see in the Plains. (I see a lot of them when I visit my in-laws in South Dakota, for instance.)

Before Europeans came into the picture a zillion years ago, lightning or fires set by Native Americans meant the eastern redcedars only lived in small canyons, ravines and outcroppings.

Now, eastern redcedars are spreading super fast across the Oklahoma landscape. Cedar smells great, doesn't it? But the oils that cause that nice aroma turn the trees into firebombs when it gets dry. Basically throw flammable oil on a discarded Christmas tree and thats what you get when eastern redcedars get hit by wildfires.

Instead of low flames skittering across open grasslands, you get the wildfires hitting groves of these trees, creating hot, big, explosive flames that are extremely dangerous, and more likely to set nearby homes and other structures on fire.

Bottom line: The past three years might be a fluke in Oklahoma wildfire history. But the real fear is that this could be a tragic, dangerous new normal for the Sooner State.