Cloud seeding continues despite ‘weird’ weather
Sky-Hi Daily News
Clouds. Topography. Wind. Temperature. Moisture. Get the ideal combination of these elements and snow dumps in the mountains of north central Colorado.
This winter, scientists have been keeping a close eye on the weather in Grand County, hoping to catch the right kind of clouds headed in the right direction to give storms the little boost they need to produce more snow.
Cloud seeding in Grand County is being funded by the organizations that stand to benefit most from big snow in the mountains – those who supply drinking water to metropolitan areas along the Colorado River and those who provide snow- and river-based recreation. While this is not the first cloud seeding project in the area, it is the first partnership of this size and scale.
Bringing together Denver Water, Winter Park Resort, the Colorado Water Conservation Board (CWCB), the State of Colorado, the Metropolitan Water District of Southern California plus water boards from four other states in the lower Colorado River Basin, the $172,000 pilot project is aimed at improving the skiing on the mountain and augmenting the water supply from the upper Fraser River all the way down the full length of the Colorado River.
Studies of the 35-year-old cloud seeding project in Vail and Beaver Creek have shown that water flows coming out of the creeks and rivers in seeded areas are 10 to 15 percent higher on average than those in nearby areas that aren’t affected by the seeding program. In some years, when storm tracks favor Vail, the seeding program has been shown to increase stream flows by as much as 35 percent.
The target for Grand County’s seeding program is Winter Park, but any hit along the Continental Divide around there is considered a success for the water users.
Using satellites, radar, local weather gauges and weather cameras, Larry Hjermstad of Western Weather Consultants in Durango and Arlen Huggins of Desert Research Institutes in Reno look for low lying storms moving out of the west, northwest or north (with a range of roughly 240 to 350 degrees on a compass) – the storms that generally have the greatest impact on Winter Park.
The conditions inside the clouds have to be just right – temperatures below 23 degrees F, high moisture content – for the seeding to work.
When a storm passes through on an upslope to Winter Park, the contractors fire continuous plumes of microscopic silver iodide particles from one of 12 generators located across the Williams Fork area and along the Colorado River southeast of Hot Sulphur and Kremmling. The generators sometimes operate for hours at a time, depending on the length and strength of the storm system passing through.
The seeded clouds can drop snow as far as 20-50 miles away, but the sweet spot for fallout is in the 10-15 mile range, and the system is fairly accurate.
“It’s the difference between a shotgun and a rifle. We are not a rifle,” Hjermstad said.
In the past 35 years, the mechanics of cloud seeding have changed little, although improved weather reading since the 1970s has helped accuracy and increased cost effectiveness, Hjermstad said.
“We have been trying to improve our operation by adding generator seeding sights, but the way we select storms and the way we seed them hasn’t changed.”
Together, the researchers have seeded more than 20 storms in Grand County since November.
“This has been a really weird year,” Hjermstad said. Storms have been coming out of the south/southwest or north/northeast rather than the west, northwest and north. “Some folks associate it with El Nino.”
In a bad year, when the storms aren’t tracking right, not even cloud seeding can help bring the snowpack back to normal, Huggins added.
Decades of experience
Denver Water has been funding cloud seeding projects in the upper Fraser Valley on and off for two decades. It funded a program in the early 1980s and again in 2002/03 and 2003/04. But the program was halted – primarily for funding reasons – until this year when the new partnerships were formed, said Steve Schmitzer, Manager of Water Resources Analysis for Denver Water. This partnership has given the project the strength of scale. The partners are spending $110,000 with Western Water Research, which is running 10 manual generators (operated by private property owners), and $62,000 with Desert Research Institute, witch is running two remote generators (operated by cell phone) in the area.
In the past five years the state of Colorado has contributed about 20 percent of the funding to local cloud seeding programs like this one, said Joe Busto, weather modification program coordinator for Colorado Water Conservation Board. States along the lower Colorado River Basin have contributed an additional 20 percent through a water augmentation agreement.
Local organizations such as Denver Water and Winter Park Resort have funded the other 60 percent of the programs.
This year CWCB is spreading about $320,000 to programs around the state, including Winter Park, Vail, Gunnison, Grand Mesa and the San Juans, Busto said.
Schmitzer and Doug Laraby, planning director for Winter Park Resort, said they plan to evaluate the effectiveness of the program at the end of the season to determine whether to move forward with it next year. As for the state’s contribution to the program, Busto said tight budgets might cut funding for the programs next year.
This year’s cloud seeding program in Grand County is scheduled to continue through the end of March.
– Reid Armstrong can be reached at 970-887-3334 ext. 19610 or email@example.com.
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