Recent storms provided little drought relief for Colorado

State Climatologist Nolan Doesken sat in his Foothills Campus office at Colorado State University last week and watched the smoke from the Galena Fire change color as the fire moved from grass and brush to trees exploding into flames.

“It was very disturbing to see that even after a fairly cold winter, our forests are still so dry,” said Doesken, a senior research scientist at CSU.

“We can’t blame it on a warm winter,” said Doesken, who is the official drought record keeper in Colorado and provides input each week to the U.S. Drought Monitor. “It’s just indicative that many areas have not begun catching up from last year’s deficits yet. A few places have made a little headway, but overall, the state remains drier than average for this time of year. Even with a couple of decent late winter storms, mountain snowpack remains low and we haven’t come close to replenishing our depleted soil moisture.”

Colorado’s drought statistics, as of March 18, according to Doesken:
• 89 percent of the state is in severe or worse drought
• 48 percent of the state is in extreme or worse drought
• 21 percent of the state is listed as exceptional drought

Exceptional drought (D4 – dark red on the U.S. Drought Monitor maps) is the worst category of drought and is often associated with harsh impacts such as crop failures and cattle sales, Doesken said. The U.S. Drought Monitor is based at the University of Nebraska at http://droughtmonitor.unl.edu/.

“Exceptional drought, D4, is equal to the kind of situation you’d only see once in any 50-year time period,” he said. “This is not unlike the extreme conditions that eastern Colorado had in the early and mid-1950s and back in the ‘30s.”

Doesken captures much of his information from volunteers who participate in the Community Collaborative Rain Hail and Snow Network, or CoCoRaHS, which consists of 17,000 volunteer precipitation monitors in all 50 states who report daily precipitation that assists scientists and meteorologists around the country. CoCoRaHS has 3,000 volunteers in Colorado alone.

“Since the summer of 2011, many areas of the states have fallen behind average precipitation by 6-10 inches or more,” Doesken said.

“It’s not like we need 10 inches of precipitation or 120 inches of snow all at once to get out of this drought, but what we do need is to promptly get back on a trajectory of regular, periodic wet spring storms, ideally accompanied by cool weather. What we had a week ago – that was very beneficial to parts of eastern Colorado but it did not get all of the state. The storms this weekend put down quite a bit of snow in the mountains, and that’s good, but it was still far from what is needed.”

Current (March 18) snowpack for basins in Colorado compared to normal:
• Southwestern (San Juans, Dolores region) – 83 percent
• Upper Rio Grande – 79 percent of average
• Gunnison – 78 percent of average
• Upper Colorado – 77 percent of average
• Yampa/White River – 77 percent
• Arkansas River – 73 percent of average
• South Platte – 69 percent

“Our mountain snowpack has made some improvement as we’ve moved through March,” Doesken said. “But all along we’ve said we’ve only had a 10 percent chance of recovering to a near normal year and a 90 percent chance that we would end up below average. The likelihood of improving to above average remains 10 percent or less.”

The one redeeming factor, Doesken said, is that March temperatures have been much cooler than last year. This time last year, temperatures were in the 70s at lower elevations and in the 50s and 60s in the mountains. Snowpack was already melting and we were headed down a dangerous road toward drought.

“That has not been the case this year,” Doesken said. “That’s a good thing. Spring is an incredibly important time of year for Colorado’s water supplies, and we still have several weeks of potential spring storms ahead of us.”