WESTERN SLOPE – Simply put, the summer fire forecast on the Western Slope is bleak and it will be for some time. Forecasters say the hot, dry and windy conditions are here to stay, and may resemble the last major drought to hit the area, back in 2002.
Forecasters at Geographic Area Coordination Center’s Rocky Mountain Area office in Lakewood say most of the Rocky Mountain region will experience average fire conditions this summer.
Then there’s the Western Slope, where a hot and dry weather pattern is expected to lead to above-average fire potential.
“Right now, we are approaching critical dryness,” Rocky Mountain Area Fire Meteorologist Tim Mathewson said Tuesday. “A quick and early snowmelt, above average temperatures, periods of low humidity, and high winds all have resulted in very dry fuel conditions across western Colorado. Right now, it’s most critical across southwestern Colorado below 8,000 feet.”
Mathewson cited a list of variables causing the dry conditions and they are all rooted in the La Niña climate pattern, in place since the summer of 2010. After an impressive start to the 2011 winter, when storms brought snow to most of the West, La Niña shifted from a neutral pattern to a classic pattern, causing storms to precipitate over the northern Rockies, and leaving many areas in the southern Rockies, including the Western Slope, with large precipitation deficits.
“This storm track took the low pressure systems and surface fronts up to the north and northern plains,” Mathewson said. “It left us with very warm conditions, drier-than-average conditions, a lot of wind and well-below-average amounts of snowpack.”
Indeed, the Natural Resources Conservation Service reports snowpack levels are well below average in Colorado, with the statewide average sitting at just 20 percent. On the Western Slope, the San Miguel, San Juan, Dolores and Animas river basins are at 24 percent of average, while the Gunnison Basin is at 20 percent of average. The Colorado River basin is at a mere 18 percent of average snowpack.
Unseasonably low spring temperatures have further depleted the already low levels of snowpack, with almost no precipitation. In the month of April, temperatures were 4 to 8 degrees above seasonal temperatures, with areas of the Western Slope receiving less than 50 percent of normal precipitation in that same time period.
The Saturday, May 26 high winds was typical of the weather Western Slope is now experiencing, Mathewson added. “That was a good example of the type of pattern we have seen,” he said. “Low pressure systems move into the Great Basin in Nevada, and push north and east of Colorado, leaving us with a lot of wind, warm temperatures and little in the way of precipitation. There is such a precipitation deficit on the Western Slope right now, and we are expecting more large fire activities until those fuels moisten.”
Because of the low snowpack levels, green-up and fine fuel growth is below average across western Colorado. The fine fuels that remain from last season are abundant, and not compacted, another result of low snowpack levels. The heavier fuels, associated with the timbered areas of Western Colorado, are more of a concern this fire season, as fires in these areas tend to be of longer duration and more difficult to control.
Is there an end in sight to the current dry weather pattern?
Forecasters at the GACC believe the La Niña pattern will begin to weaken during the summer period, and decrease the likelihood that current patterns will continue to support the trend of warmer, drier and winder conditions especially on the Front Range, east of the Continental Divide. If that trend slows, the transition from the current pattern is expected to slow as well. As for the Western Slope, Mathewson does not anticipate any change in the weather pattern indicating the end of the hot and dry weather anytime soon.
“I am thinking we will probably see some relief when the Southwest Monsoon develops,” he said. “That usually comes in early July, so we will have at least for or five more weeks of above-average fire potential.”
But while the development of the Southwest Monsoon may bring needed precipitation to the region, it will more than likely bring a large amount of lightning with it.
“Usually that first push of the monsoon results in several ignitions,” Mathewson said. “The ultimate outcome of this fire season will be based on ignition. That is the wildcard here. There’s not been a whole lot of natural ignition on the Western Slope so far but we are expecting it.”
While it isn’t as severe yet, Mathewson does see parallels to the drought of 2002.
“That was a big drought year for all of Colorado,” he said, although “that drought was very widespread, and this one is more confined to the higher elevations on the Western Slope of Colorado.
“We will have another update in early June,” he added, “but I really don’t see any changes to what we have going on right now.
“I don’t see any sign of precipitation coming anytime soon on the Western Slope.”
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