Wildfire fear hits fever pitch
It’s hard to contemplate the fire danger in South Canyon near Glenwood Springs being worse than on July 6, 1994, when a wildfire blew up and killed 14 firefighters.
But here we are.
Current western Colorado fire conditions also are drawing comparisons to those that contributed to an even earlier firefighter tragedy. In 1976, frost had killed oak brush foliage and contributed to flammable conditions on land near Battlement Mesa where a wildfire took three lives later that year. This year oak brush and other mountain brush species in western Colorado have suffered one or two frosts that killed up to 40 percent of the foliage.
Consider just about every factor right now, and it all points to the possibility of a summer wildfire season in western Colorado like none that has preceded it.
Drought-parched vegetation, frost kill, windy days, a build-up of undergrowth, an increase in beetle-killed forests, and the likely arrival of a monsoon season that will start off with more lightning than rain all are making for frightening conditions in western Colorado.
“We’re right here at the ragged edge. We really are at a place with the fuel conditions where we’ve never been before,” said Clay Fowler, fire management officer for the Upper Colorado River Interagency Fire Management’s Central Zone.
“... The conditions right now are dangerous. They really are dangerous.”
Starting Friday, elevated fire restrictions will take effect in Colorado National Monument, on Bureau of Land Management land in northwest Colorado and in the White River National Forest. Among other things, that means all campfires will be banned, including even those in fire pits and grates in developed campgrounds.
The fire danger in higher elevations where the increased restrictions are taking effect has never been more extreme in recorded history. In lower elevations, conditions are similar to the last major Colorado wildfire year of 2002. Depending on elevation, dead wood from 3 to 8 inches in diameter has fuel moisture levels of 3.5 to 8.5 percent, compared to 12 percent for kiln-dried lumber.
Fowler said low-elevation fire conditions this severe have been found only 1 percent of the time since those conditions first were tracked.
The live fuel moisture of oak brush in South Canyon is currently 100 percent, meaning the weight of the moisture is equivalent to the weight of the biomass that contains it. On July 6, 1994, it was 125 percent, meaning there was more moisture weight than biomass weight.
Current sagebrush live fuel moisture levels are in the mid-90-percentile range, and in some places moisture levels are so low that plants may start dying.
“Anything below 125 means it’s not going to slow the fire down at all,” Fowler said.
He said the current probability of ignition is 100 percent, indicating there’s a 100 percent chance that if you threw a match on the ground and it hit receptive fuel, it would start a fire.
Compounding problems is the high level of such receptive, ground-level fuel. In terms of reservoir water storage, Colorado has been fortunate that this year’s drought has followed a couple of wet years in which storage was built up. However, that previous moisture fostered heavier growth of grasses and other ground-level fuels, unlike in the bad wildfire year of 2002, which was a third dry year.
There’s been less ground growth this year, but previous growth never was compacted due to a lack of snow, leaving it fluffed up and primed to burn.
“There’s a pretty deep fuel bed out there of ... fine fuels that fire will move through pretty badly,” Fowler said.
Also contributing to the fire danger are windy conditions that both help dry out vegetation and feed and drive a fire once one strikes.
As it turns out, Grand Junction’s average daily wind speeds in May and June have been slightly below the annual averages for those months, and the averages for the same months of 2002.
Still, John Kyle, data acquisition program manager for the National Weather Service in Grand Junction, noted that even a mildly windy day can have major gusts, like the 46-mph one recorded last Friday.
He said both this spring and last seemed windier than normal.
The average of peak daily gusts through the first 19 days of this month is 32.5 mph. That compares to 36.4 mph for the same part of last June, but just 30.2 mph for the comparable period of June 2010. This month’s peak gust of 52 mph compares to an average June peak of 55 mph, although May’s peak of 59 mph tied the May average of 59 mph.
This is normally a windier time of year to begin with. Kyle said this year’s wind may partly be the result of energy resulting from cloud production that’s inadequate to produce rain but creates wind instead.
Rain should eventually come, as it does most years, with the arrival of the summer monsoon season. But Aldis Strautins, a hydrologist and meteorologist with the Weather Service, said it’s hard to predict when the annual monsoon will arrive and how much rain it will produce.
The monsoon brings up moisture from the Southwest, but until it arrives and establishes a pattern, it’s difficult to tell where the high pressure will set up and whether the rains will fall more elsewhere or give Colorado a consistent soaking.
Worst of all, Strautins and Fowler agreed, when the monsoon arrives, it usually starts out with a period of dry lightning before bringing regular rains.
“For those first few days it can get right sporty,” he said.
Fowler said fire’s a certainty this year once the monsoon season arrives.
“What we’re trying to do with these (fire) restrictions is to really keep the human-caused fires to near zero so our troops are not nearly exhausted when the lightning fires come,” he said.
Fortunately, he said, lightning fires often strike more remote areas where there’s less of an immediate threat to homes.
Fowler hopes the monsoon eventually will improve the situation.
“One long day of drizzling rain would make a significant difference,” he said.