Winter wildfires a rarity for Reno area but warming climate could make them more common

Winter wildfires a rarity for Reno area but warming climate could make them more common

04 February 2012

published by www.rgj.com


USA — It happened not once but twice.

Two rare winter wildfires roared through Reno-area neighborhoods, destroying more than 50 homes, changing lives and leaving some wondering whether the destructive events might be a sign of things to come.

November’s Caughlin Fire was followed almost two months to the day by the Washoe Drive Fire on Jan. 19. The fires were strikingly similar – both the result of high winds associated with a dry cold front pushing flames through brush and grass made ready to burn by an early winter of record dryness.

The combination was explosive.

“The fire behavior was intense as it can probably get,” Reno Fire Chief Michael Hernandez said. “Those two fires were more destructive than any other fires we’ve had along the Sierra front in 50 years.”

The combined disasters would be remarkable in the heart of summer but instead occurred at a time of year more closely associated with problems such as trying to keep passes open that snowstorms likely closed. For the Reno-Tahoe area, the situation was unprecedented.

Dry and windy conditions lined up perfectly as a fuse for the fires but with a warming climate, invading vegetation and more people living in fire-prone areas, could big winter wildfires become the norm?

It’s impossible to say for sure, but some experts say the possibility is there.

“Is more of this going to occur? The projection is yes,” said Thomas Swetnam, a forest ecologist and wildfire expert at University of Arizona. “Are we going to see more winter fires? Yes, if it’s warm enough or dry enough.”

Swetnam was involved in a 2006 study that indicated increasing fire activity is associated with rising spring and autumn temperatures and an earlier spring snowmelt in western mountains.

The study concluded that recent wildfire frequency spiked to nearly four times the average experienced between 1970 and 1986, with the area burned more than six-and-a-half times previous levels.

The average length of the fire season increased by 78 days between 1987 and 2003 compared to 1970 to 1986, with fires starting earlier and burning later into the season, the study found.

Winter fires “are still pretty unusual” but could become more common under the proper conditions, particularly when factors such as the spread of highly flammable invasive vegetation such as cheatgrass are taken into account, Swetnam said. That could be particularly true when wet winters nourishing bumper crops of grass are followed by dry winters – a situation now existing in the Reno-Tahoe area.

Linking this dry winter and the fires it helped spawn to climate change is “probably kind of a stretch” but as temperatures warm it’s likely there will be an increasing number of large and destructive blazes across the region, said Roger Walker, a forestry and wildfire expert at University of Nevada, Reno.

“In terms of historic fire cycles, what Reno experienced this year is an anomaly,” Walker said. “We probably are going to see more and more fires. The intensity will increase, the prevalence will increase and the acreage that burns will increase.”

Nevada State Forester Pete Anderson agreed it’s difficult to link recent events to any long-term trends but said the possibility should be considered.

“It’s almost hard to get your mind around it ­– you’re seeing fire activity you would normally see in July,” Anderson said of the two recent blazes that could have been far more destructive than they actually were.

“We do have a changing environment occurring and we have to be better able to prepare ourselves for these kind of events,” Anderson said. “It may in the end change the way business is done.”

That’s in part because many fire agencies – including the Nevada Division of Forestry, the U.S. Forest Service and U.S. Bureau of Land Management – depend heavily on a cadre of firefighters that are recruited on a seasonal basis. Most are on duty from late spring through the summer and are gone by mid-October.

If more fires do start burning in winter months, some serious changes in institutional thinking might be required, Walker said.

“It’s true that if we’re going to have more of these unseasonal fires, that staffing may require an adjustment,” Walker said. “How they are going to do that with their budget constraints, I’m not sure.”

And trying to guess what fires are going to do on any given year is all but impossible, Walker said.

“It’s a hard thing to do. It’s almost like predicting the stock market,” he said.


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