Wet, then dry, but snowpack balances out
Glenwood Springs Post Independent
After a wet January and dry February, snowpack in western Colorado is hovering around normal. As of Friday afternoon, gauges across the Upper Colorado River Basin were registering a snow-water equivalent 102 percent of the 30-year median for the date. The Roaring Fork Watershed trailed slightly with 90 percent of the median.
“We had that pretty big snow cycle that caused powder days and snow days at the end of January. Otherwise, it was looking a bit dry, and February was particularly dry,” said Roaring Fork Conservancy education and outreach coordinator Liza Mitchell. “Not only is it important how much more precipitation we get, but the timing of the warming can have a huge impact.”
Snowpack in the high country generally peaks around April 10, when melting outpaces snowfall and rivers begin to rise. Last year a relatively light snow year peaked in mid-March, with a potentially bad fire season averted thanks to a cool, wet spring.
This year has already surpassed the 2015 peak, but is still well behind the robust winter of 2014.
That may seem strange to residents of Glenwood Springs, where more than 2 feet of snow fell in January — including 7 inches on Jan. 17 alone — with almost as much in December. It’s not the precipitation on the valley floor that makes the big difference, though.
“We get more melting cycles down in the lower elevations. The water supply is more in the mountains where it’s kept longer due to temperatures,” Mitchell said. “The snowpack we have in the mountains really acts as a natural reservoir. Over the course of the year, it’s going to melt and keep our rivers running all summer long.”
As such, a better indicator might be Bison Lake on the Flat Tops, where depth and snow-water equivalent are measured each March 1. This year, that came to 56 inches of snow, or about 17 inches of water if you melted it down. In 2015, it was 49 inches deep with 13.4 inches of water, and in 2014, 74 inches and 20.9 inches, respectively.
What that spells for rafters and firefighters come summertime remains to be seen.
Even the National Weather Service’s three-month outlook looks like a mixed bag, calling for both above-average precipitation and higher temperatures in western Colorado.
“You don’t often see those together,” said Norv Larson, a meteorologist for the weather service in Grand Junction. “It might mean warm temperatures during the day with thunderstorms developing in the afternoon — our typical monsoon pattern.”
He shied away from linking the weather to El Nino conditions in the Pacific.
“We’re one of those areas that’s transitional, so it depends on where the pattern sets up,” he said.
There’s some time before any big decisions about water or fire have to be made.
“Historically, March and April are wetter months, so I think it’s reasonable to expect some more precipitation,” Mitchell said.
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