Aspen Journalism is compiling a data dashboard highlighting metrics of local public interest, updated weekly.
Increasing snowpack but still below normal
Snowpack in the Roaring Fork basin has gone up since last week, reaching an average of 5.5 inches of snow-water equivalent per site on Dec. 25, or 90% of median, according to NRCS.
SNOTEL sites that monitor snowfall throughout the winter measured the snowpack at Independence Pass at 64.2% of median on Dec. 25 with a “snow water equivalent” (SWE) of 4.3 inches, up from 4 inches but down from 69% of normal on Dec. 17. Last year on Dec. 25, the SNOTEL station up the pass (located at elevation 10,600 feet) recorded an SWE of 6.1 inches.
The monitoring station at McClure Pass, located at elevation 8,770 feet, recorded a SWE of 4.6 inches on Dec. 25 or 81% of median. That’s up from a SWE of 4 inches on Dec. 17. Last year, on Dec. 25, the station measured a snowpack holding 6.8 inches of water.
On the northeast side of the Roaring Fork Basin, snowpack at Ivanhoe, which sits at an elevation of 10,400 feet, reached 6 inches of SWE on Dec. 25, or 107.1% of median.
Snowpack at North Lost Trail, which sits at an elevation of 9,219 feet, has reached 6.4 inches of SWE on Dec. 25, up from 5.9 inches last week.
Snowpack at Schofield Pass reached 9 inches on Dec. 25, which represents 78% of median. That’s up from 8.5 inches on Dec. 17. Schofield Pass sits at an elevation of 10,700 feet between Marble and Crested Butte.
Snow water equivalent — the metric used to track snowpack — is the amount of water contained within the snowpack, which will become our future water supply running in local rivers and streams.
Lake Powell’s water levels keep decreasing slowly
Lake Powell‘s water levels peaked in early July and are now decreasing. On Dec. 25, the reservoir was 36.37% full (based on updated 2017-18 sedimentation data). That’s down from Dec. 17, when the nation’s second-largest reservoir was at 36.55%.
Last year, on July 1, 2022, the Bureau of Reclamation revised its data on the amount of water stored in Lake Powell, with a new, lower tally taking into account a 4% drop in the reservoir’s total available capacity between 1986 and 2018 due to sedimentation. Aspen Journalism in July published a story explaining the that drop in storage due to sedimentation. We will be now using the 2017-18 sedimentation data only.
On Dec. 25, 2022, the reservoir was 23.84% full.
On Dec. 25, Lake Powell’s elevation reached 3,569.5 feet, or 130.5 feet from full pool, which is down from 3,570 feet on Dec. 17. Last year, on Dec. 25 the reservoir reached 3,525.24 feet in elevation, or 174.76 feet from full pool.
The “minimum power pool” for turbines generating hydropower at the Glen Canyon Dam is 3,490 feet, and 3,525 feet has been set as a buffer to ensure that the reservoir and the turbines can continue to function properly.
Above-normal air temperatures reported before Christmas at ASE
High air temperatures at the Aspen airport went from 39°F on Dec. 11 to 48°F on Dec. 20, which is about 15 degrees above normal. Meanwhile, low temperatures went from 10°F on Dec. 18 to 24°F on Dec. 21.
It’s worth noting that this chart has been updated with the 1991-2020 U.S. climate normals (last week’s version was using the 1981-2010 climate normals).
Clean air in Aspen
The air quality in Aspen was “good.” The air quality index for ozone ranged from 30 on Dec. 19 to 39 on Dec. 25.
