State Narrowly Avoids Ongoing Drought Conditions with Winter Storms, State Climatologist Says

Note to Editors: A photo of Nolan Doesken and more information about CoCoRaHS can be found with the news release at http://www.newsinfo.colostate.edu/.

Enough snow fell on Colorado in the last five weeks of 2007 to avert dangerously dry conditions that were once again emerging, said Nolan Doesken, state climatologist and senior research associate at Colorado State University.

Most of the state received significant moisture from December storms. After the snow, much of the state also experienced subzero temperatures, making this the coldest December since the early 1990s for much of the state, according to initial reports from Colorado State’s volunteer precipitation monitoring network and the National Weather Service.

Mountain snowpack levels that had gotten off to a very slow start this winter have now climbed to near average for this time of year in the northern mountains of Colorado and to more than 140 percent of average in the southern mountains based on data from the U.S. Department of Agriculture’s Natural Resources Conservation Service. The recent storm that clobbered the California Sierras also dropped several feet of new snow in the mountains of southwestern Colorado.

A few weeks ago, weather and water watchers were getting nervous.

"Going into the end of November, it was very touch and go – drought conditions were redeveloping over the eastern Plains, and snowfall in the mountains was much less than average," Doesken said. "Weather patterns changed abruptly. We went from being dangerously dry and warm to being back on track for an average winter."

Doesken is still collecting final precipitation statistics for 2007 from the National Weather Service and the volunteer weather network he created a decade ago. The Community Collaborative Rain, Hail and Snow Network, or CoCoRaHS, now has some 1,000 volunteers around Colorado to take daily measurements of rain and snow with a simple rain gauge and to occasionally measure hail with foil-wrapped Styrofoam pads.

Data gathered by volunteers provides important daily and long-term decision-making information on drought and water supply for agricultural, recreation, utility providers, resource managers, teachers, scientists and homeowners. The program has been so successful that Doesken has expanded it nationally into 26 states; CoCoRaHS will add at least another nine states this year.  

"There are still many parts of the state of Colorado where we get little information, so we are always looking for more volunteers,"  Doesken added.

Some December weather highlights from around Colorado:

– In the southwestern part of the state, the area including Durango, Cortez and Pagosa Springs benefited from an average of 5 inches of moisture contained largely in rain and wets snows at elevations below 9,000 feet.

– Grand Junction received more than 2 inches of precipitation in a two-week period in December and experienced temperatures that were more than 3 degrees below average for the month.

– The Gunnison River valley experienced temperatures in the minus 20s on several occasions. Snow accumulation there is now well above average.

– The Upper Colorado region from Glenwood Springs to the Continental Divide received moisture that’s 103 percent of average.

– Northwestern Colorado, which was very dry last winter, received generous snowfall since mid-December. The water content in the snowpack remains slightly below average at 95 percent.

– The South Platte region from Fairplay to the Wyoming border has been cold and windy with snowpack recently improving to 98 percent of average.

– One of the coldest spots in the state was Antero Reservoir south of Fairplay in South Park with 13 days of minus 20 degrees or colder. The coldest day was Dec. 16 with minus 37 degrees.

In general, the eastern Plains are benefiting from some moisture from snow cover, giving the region above-average precipitation – although still below last year’s record levels, Doesken said. Kit Carson County in east-central Colorado, which includes Burlington, received three or four times the average amount of moisture content it normally receives in December.

"It’s really a picture of optimism, considering that the forecast calls for a greater likelihood for warmer and drier than average conditions resulting from La Nina conditions in the tropical Pacific," Doesken said. "So far, where it was predicted to be driest is where some of the wettest weather has occurred."

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