Southern Colorado climate update

by Carol Dunn
HUERFANO- The spring storm that moved through the area on Monday and Tuesday brought much-needed moisture, but it is unlikely that it will be enough to make up for the 13-inch shortfall in precipitation over the past two years. State Climatologist Nolan Doesken spoke to a crowd of about 30 on March 29 in Walsenburg, telling them, “It’s not just a one year drought we’re in, but two solid years.” He confirmed that catching up on moisture won’t be easy. “Lack of water is a big deal,” he said. “Even if we get small rain events, evaporation can be three to four inches per month in summer.”
Doesken explained recent climatic conditions in our region, the long term historic perspective of those conditions, and prospects for the rest of spring and summer. A nationwide drought in 2011 gripped over a third of the country. The dividing line for moisture was roughly along I-70 in Colorado, with an extreme shortage from Monument south to the tip of Texas.
Doesken, who works at the Colorado Climate Center at CSU and founded CoCoRaHS (Community Collaborative Rain Hail & Snow Network), told the audience, “Drought is a big deal in Colorado.”
Using a series of charts showing average precipitation in Huerfano County for the past 77 years, Doesken demonstrated that “dry” is more normal in this area than “wet.” He said, “The times of high precipitation were an exception, and you got used to it. It’s still very dry here and getting drier.” Doesken said March and April are critical times for moisture. “This should be the wet season,” he said. “You should have had two inches of precipitation this month.” An audience member replied, “Well we’re within two inches.”
The immediate prospects for moisture are “grim.” Huerfano County precipitation records go back to 1935, and the wettest year had 25.5 inches while the driest year reported about 9 inches. The average is 16 inches of precipitation per year. “You will deal with drought multiple times in a lifetime,” he told the audience, predominantly members of the agricultural community.
March 2012 was the driest and warmest March in 120 years along the northern Front Range. Doesken said, “Hot years and dry years tend to go together. If you’ve just had a really dry year, the next year should be better. But I’m not seeing it quite yet.”
Doesken said it is not likely we will catch up on precipitation, based on current conditions. Beyond a two-week forecast, climatologists tend to look at ocean temperatures for climate clues. The current La Niña conditions, cooler than average temperatures in the tropical Pacific Ocean, are associated with dry and warm weather in our area (leading to drought). Doesken said the ocean holds much more energy than the atmosphere, and it can give reliable clues about what to expect as far as climate and weather patterns.
Doesken tapped into the Climate Prediction Center for conservative estimates of climate conditions for the next year. “It’s looking like it’s going to stay dry for a while longer,” he said. A dry March is usually followed by a dry April and May, so southern Colorado is expected to continue to be dry into June. July, August and September are expected to be hot with above average temperatures and an equal chance of wet or dry conditions. Computer models suggest a relatively strong El Niño by August, bringing moisture back to the area. However, Doesken stressed, “Climate relationships are not that easy.”
Doesken encouraged people to sign up to be CoCoRaHS volunteers so more precipitation data can be collected from Huerfano County. See www.cocorahs.org for more information.
The climate update seminar was sponsored by Huerfano County Commissioners, Huerfano Basin Stockgrowers Association, Upper Huerfano Conservation District, CSU Extension, and the Natural Resources Conservation Service.