Drought a regular visitor to Colorado
April 9, 2013
EAGLE, Colorado – The aqua apocalypse is not upon us, yet, says Nolan Doesken, Colorado’s state climatologist.
“Drought is a regular visitor to Colorado,” Doesken said. “This has been going on for hundreds and hundreds of years.”
“The whole state is dealing with it for the second year in a row, and the third year in a row in southeast Colorado. Warmer temperatures, especially in spring and summer, are making matters worse,” Doesken said.
Doesken was in town last week to talk to the Eagle River Watershed Council’s Water Wise Wednesday crowd. He asked the question, “Is drought permanent or periodic?”
The answer is “Yes.”
Climatologists are weather historians and climate accountants, he said, tracking and analyzing data. Colorado State University, where he works, has been collecting weather data since the 1880s.
By the 1890s Colorado had a system of weather stations. Eagle County’s was in Red Cliff, the county seat at the time.
And what have we learned? In Fort Collins and other parts of the state, precipitation can vary by a factor of four, from year to year, Doesken said, and it’s impossible to predict more than a year or two in advance.
“Trends are hard to detect because of the wild variations in temperature and precipitation,” Doesken said.
But we’ve been having a run of warm springs, which is troublesome, but 1934 was warmer. The summer of 2012 was the hottest ever, Doesken said. Last year, you’ll recall, was pretty much awful all over the state.
“If dry years come back to back to back to back, they’re a problem,” Doesken said.
This year isn’t great, Doesken said.
“It’s better than last year and better than 2002, but not great,” he said. “The depletion of statewide reservoirs is bad, but not as bad as 2002.”
And 2011 tells a larger tale. Colorado has such diverse geography that it’s pointless to calculate statewide averages.
“Colorado would be a desert if it weren’t for the elevation that squeezes the last bit of moisture out of Pacific storms that roll through,” Doesken said. “We’re on the northeast edge of the desert southwest. We get lots of sunshine and sunshine makes people happy.”
Vail is supposed to average 2.5 inches of precipitation a month. April’s the highest at 4.5 inches. It goes dry again in June-August, 1.5 inches, but that’s OK because we’re tired of snow and rain and are ready to take a hike and play outside, or ride in the car with the top down and the stereo up.
A few miles away in Eagle and Gypsum are mountain desert climates.
Last summer Las Animas tied the state’s all time high at 114 degrees, which was set during the Dust Bowl of the 1930s – also in Las Animas.
Some things remain roughly the same.
The midwinter months, December-February, are the driest of the year in the high country. Snow melts out about the same time each year, except when it doesn’t. It was gone by early April last year. The July monsoons help with their afternoon thunderstorms, Doesken said.
As for this year we’re making progress, but the whole state is still below average, Doesken said.
“There are a couple storms rolling through in the next week and temperatures will stay cool through mid-April. But the hope for a miracle finish to give you all the water you were hoping for is getting very, very thin,” Doesken said.
It’s all about the snow/water equivalent. That’s the amount of water contained in the snow we get. Powder is great to ski, but heavy and wet snow contains more water.
The Natural Resources Conservation Service measures snow water equivalent at several Snotel sites, including one on Vail Mountain that reads 12.5 inches of snow water equivalent. Normal is 20 inches for early April.
At this time last year Vail Mountain’s Snotel reading was 2.6 inches.
In the drought year 2002 on this date, the Vail Mountain site was at 14.2 inches of snow water equivalent.
Vail Mountain’s snowpack peaks around April 25 most years, said Diane Johnson with the Eagle River Water and Sanitation District. In a normal year the spring runoff ends in late June.
Summer streamflows are forecast to be low for two reasons, Johnson said.
First, the snowpack is lower than normal, although higher than last year’s woeful levels.
Second, two consecutive thin snowpack years have left the land dry.
“The land doesn’t have much moisture in it, so when you have a snowpack this low and it starts to melt, a lot of it gets absorbed into the soil,” Johnson said.
Staff Writer Randy Wyrick can be reached at 970-748-2935 or firstname.lastname@example.org.