Wildland firefighters say snowpack may bring busy fire season; wildfire science

Wildland firefighters say snowpack may bring busy fire season; wildfire science

06 March 2014

published by www.stgeorgeutah.com

USA — In 2005, the local landscape changed drastically after wildfires decimated southwestern Utah. Since then, the conditions are prime for further devastating wildfire seasons. As a multitude of local and regional fire agencies prepare for the fire season, leaders discussed this year’s outlook at a “table top training” at Dixie Applied Technology College’s Tonaquint Center campus in St. George, Tuesday.

Firefighters role played wildland fire scenarios and focused especially on this year’s conditions, which in short are a combo of low snowpack and lots of dry grasses.

Because of the heavy rainfalls the region had last fall, ample amounts of grass have grown across Southern Utah – firefighters call these grasses “fine fuels.” When sparked, these native and invasive grasses, like cheat grass, can burn as fast as a human can jog. It’s not uncommon for a fire to burn 5 mph with a wind behind it, Arizona Strip Bureau of Land Management’s Fire Management Officer Mark Rosenthal said.

Wildland grass fires can move faster given the right conditions, even reaching 14 mph forward rate of speed in some cases.

“Cheat grass is a real serious issue for us,” Rosenthal said. This year, “we see that fine fuel crop out there;” he said, “that has potential for a very busy fire season.”

However, potential fires and actual fires are two different things.

“I’ve given up on predicting,” Dixie National Forest Public Affairs Officer Joe Harris said. Harris thought 2011 had perfect conditions for a devastating fire season, but that never came true. This year, besides prolific grasses, another similarity to 2011 in the fire season outlook is that snowpack is low.

In 2011, snowpack on the Pine Valley Mountains was low and this year it’s lower. In fact, as of March 1, the snow water equivalent – a common snowpack measurement – on a sensor site on the Pine Valley Mountains is almost 1/3 of what it was at the same time in 2011. Furthermore, at the same sensor site, Gardner Peak, snow depth is down from 53 inches in 2011 to 25 inches this year.

The Gardner Peak sensor numbers can be found on the SNOTEL section of the National Weather and Climate Center’s website. Harris checks these numbers regularly to prepare for fire season. Full statistics for this sensor site can be found here.

On years with higher snowpack, it’s more typical for fires to burn down low but fizzle once they come in contact with the snow-fed brush in the higher elevations on the Pine Valley Mountains. Southwestern Utah typically has either a high elevation fire season – more in the mountains – or a low elevation fire season, Harris said. 2011 was set up for both.

That year, we had unexpected heavy rains in May and heavy rains bring more fast drying grasses. Situations like this can potentially lead to massive fires that burn all the way up the mountainside.

“Everybody (preceding the fire season 2011) was running around like their hair was on fire,” Harris said, “and it just never showed up.”

Although late spring rains are yet to be seen this year in Southern Utah, even if those rains do come like they did in 2011, there’s no guarantee we’ll have a heavy fire season.

Even with perfect fire conditions, if there are no ignitions, there are no fires. In 2011, despite perfect conditions for wildfires that year, the lightning never came, and the human caused ignitions never happened, Harris said.

This is a stark contrast to 2005 – Southern Utah’s biggest fire year in recent times – when there were many ignitions. Ignitions that sparked massive 30-40,000 acre fires from the Beaver Dam slope, down across the Arizona Strip, and along the entire Interstate-15 corridor, Roesnthal said.

In 2005, some ignitions had natural causes like lightning strikes, but many were ignitions caused by humans. Human’s can have a tremendous impact on fire season through attention or inattention. Spark arresters on ATVs, tying up chains so they don’t spark on the highway, observing camping protocols and fire restrictions can make all the difference in the number of wildland fires Southern Utah’s firefighters must face down.

After firefighters hectic 2005 season, plants started to grow back, but this time, loads of grasses that “cheat” followed suit. “Everything that burned in 2005 is now cheat grass,” Harris said.

Cheat grass came from Eurasia, and it germinates at a colder temperature than native grasses, outcompeting them and germinating earlier, literally weeding out the native grass species.

“When you get a fire that comes through, the cheat grass comes in behind and it becomes a cheat grass field,” Harris said. “Then, the propensity for it to burn goes up. These cheat grass fields are really hard to reclaim,” Harris said.

Cheat grass is known as a one-hour fuel to firefighters. “They’re called one-hour fuels for a reason,” Harris said. One hour after a rainstorm, they are totally dried out and ready to burn again.

“Our landscape is changing because of these invasives that are coming in. We have the potential … every year,” Rosenthal said, ”to have 30-50 fires going in color country at any time with the potential for many of those fires to get big.”

However, Harris said, “to be honest with you, the conditions are almost there every year.”

The interagency wildfire district of color country is responsible for dealing with these fires. Color country covers a vast area of land from Beaver south to the rim of the Grand Canyon and from the Nevada state line, east all the way in to the Escalante area.


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