Colorado Farm Show speaker: Eastern Plains of Colorado might be in for hot, dry summer
It might be another warm, dry summer, similar to conditions that have prevailed on the Eastern Plains since September of last year, and conditions that could imply the region is headed for another drought.
Nolan Doesken, state climatologist at Colorado State University, drew his normal large crowd at the 2011 Colorado Farm Show on Wednesday afternoon. He said he based his prediction on the best information he could get from private-sector weather forecasters, leaning heavily on Klaus Wolter at the University of Colorado, who Doesken said “is a pretty thorough student of weather.”
The problem, Doesken said, is La Nina, a cooling of water temperatures in the Pacific. Temperatures dropped late last year at one of the faster rates in recorded history. Any time La Nina prevails, eastern Colorado is susceptible to warmer and drier conditions. Those conditions have been around the region since September of last year; the major rainstorm/snow storm for the region was in August of last year, Doesken said.
How long those conditions remain – and nobody has a definitive answer on that – will go a long way in determining whether the region is headed for another drought.
There are, however, a lot a variabilities attached, Doesken said. There are also exceptions to the rule, similar to those that most recently occurred in 1999. That was a very wet year, but the next five years resulted in one of the worst drought periods on record, particularly in 2002, which was the driest and hottest on record.
“The good news is there is a lot of water in the headwaters of our rivers, and most of our reservoirs have good water,” Doesken said.
In fact, snows on the western side of the Continental Divide have developed a snowpack that is four to six weeks ahead of what is normal for this time of the year, and because of that, the Northern Colorado Water Conservancy District may not have enough room to put all of the runoff in Granby Reservoir, the largest in the northern part of the state on the Western Slope.
“They are looking at the potential of spilling from Granby this spring, letting water out and back into the upper Colorado River,” Doesken said, which he noted is good news for those on the Western Slope, but not all that good for those on the eastern side who get a supplemental water supply from Granby through the Colorado-Big Thompson Project.
Doesken was quick on his prediction of how long La Nina conditions might last.
“I don’t know,” he said.
But he was also quick to point out that spring and summer thunderstorms have their own agenda, which may play a major role in weather conditions.
“Thunderstorm systems tend to do what they do in spite of long-term patterns,” he said.