NewsApril 28, 2013

Boost to Colorado Snowpack May Lessen Wildfire Risk

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Andrew Freedman

By Andrew Freedman

As recently as late March it appeared that most of the West, including Colorado, was headed for a long, and tinderbox-dry spring and summer, with the effects of a long-running drought becoming ever more apparent in the form of dwindling water supplies and destructive wildfires. Many officials feared a repeat of last year’s disastrous wildfire season, when Colorado saw its most destructive wildfire on record strike the Colorado Springs area.

And then winter finally arrived, in April, when the weather typically warms in earnest across Colorado.

Boulder, Colo., recorded its snowiest month of any month on record in April.
Credit: UCAR's Atmos News via Bob Henson.

Since the first week of April, a barrage of strong storms accompanied by record cold air produced several feet of snow in parts of the Rockies, raising hopes that some areas can avert a water resources and wildfire crisis after all. For example, Boulder, Colo., not only broke a record for the snowiest April on record, but it also broke the mark for the snowiest month of any month there, with about 50 inches so far. Record cold accompanied the snow, with temperatures staying closer to typical January values rather than April, although they have since moderated.

Before April 6, the statewide Colorado snowpack stood at just 70 percent of normal. After the spring snowstorms blitzed the state, shattering snowfall records, the snowpack increased to 92 percent of normal. The storms have mainly benefited northern Colorado, while the southern part of the state still has a below-average snowpack compared to average at this time of year.

Experts caution though that the late peak in Colorado’s snowpack does not mean the drought is over, and won’t necessarily translate to a reduced wildfire risk.

According to Mage Hultstrand, the assistant snow survey supervisor with the Colorado Snow Survey, the unusually late peak to the snowfall season may present problems of its own.

In a typical year, the snowpack in Colorado peaks around April 8. The storms pushed this year’s peak back by at least two weeks, deeper into spring when a rapid warm-up is more likely. A quick snowmelt would yield less water for the state’s rivers and reservoirs than would have been gained had the peak and melt out occurred earlier in the year.

“We had a huge boost with these storms,” Hultstrand said in an interview. “It’s really good news, but it would have been better news to have it a few months ago.”

One clear benefit of the late season snowstorms is that they delayed the onset of the Colorado wildfire season along the state's Front Range. In 2012, the wildfire season began in March, and culminated with the Waldo Canyon fire in June, which destroyed 347 homes and killed two people. 

Hultstrand said the moisture provided by the snow cover is helpful for averting early season wildfires, but that it also may encourage plant growth, which could serve as fuel for wildfires later in the season.

She said the best-case scenario would be for the weather to stay cool so the snow can melt gradually. “People are ready for spring-like weather, but it would be better to have colder weather for another month or so,” Holstrand said.

Colorado state climatologist Nolan Doesken said the summer wildfire season will be largely determined by the weather during the rest of the spring and into the summer. “This recent snow will prove invaluable in terms of adding additional snowpack to feed an improved snowmelt runoff — providing more water for summer irrigation and recreation. But in terms of fire, the benefits will be short lived,” he said in an email interview.

“It only takes a few days/weeks of hot summer temperature, low humidity, full sunshine and moderate winds… to quickly dry things out again. By mid to late June, the memory of these April snows will be gone.” 

New Mexico Faces Difficult Water Choices

While Colorado benefited from the unusual and persistent weather pattern during early spring, the Southwest missed out on most of the heavy precipitation. In New Mexico, much of the mountain snowpack has already melted. Even the northern parts of the state, which typically retain their snow cover longer, have less than 50 percent of normal snowpack for this time of year, according to Wayne Sleep, a hydrological technician with the Natural Resources Conservation Service in New Mexico.

Western U.S. snowpack compared to average as of April 1, before the heavy snows fell in Colorado. 
Credit: Natural Resources Conservation Service

Even more discouraging, Sleep said, is that the snowmelt does not seem to be raising streamflows, and runoff is predicted to be only 20 to 50 percent of average in most areas.

New Mexico is entering its third straight year of drought conditions, which is compounding problems, particularly when it comes to water supplies, as reservoir storage continues to diminish.

“It’s looking pretty rough for water in New Mexico this year,” Sleep said. “It’s getting to the point that everybody is pretty concerned.”

Vegetation that could have survived 1 to 2 years of unusually dry weather are now suffering greater impacts as the drought stretches on, Sleep said. “We may be seeing more die-off of vegetation and trees with these dry conditions . . . we’re not just looking at one year’s effects anymore.”

An abundance of dead vegetation could provide fuel for wildfires, and New Mexico has seen several large blazes in recent years, including one wildfire that threatened the Los Alamos National Laboratory in 2011. That wildfire was the state’s largest on record.

Droughts in the Southwest are projected to become more frequent and severe in coming decades due, in large part, to manmade global warming, although the current Southwestern drought has not been directly linked to climate change as of yet.

Large blazes are becoming more common in the West as average temperatures increase and spring snowmelt occurs earlier in the year. In addition, land-use changes have helped contribute to more wildfires as communities expand into previously unoccupied territory.

Compared to an average year in the 1970s, during the past decade there were seven times more fires greater than 10,000 acres each year, and nearly five times more fires larger than 25,000 acres each year, according to Climate Central research.

Other Western states, including California, also have a below-average snowpack, which could elevate wildfire risk and put pressure on water resources during the summer, which is typically dry in that area. The most recent climate outlooks issued by the National Oceanic and Atmospheric Administration call for above-average chances that the summer will be warmer and drier than average across much of the West. 

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