Aspen Journalism is compiling a data dashboard highlighting metrics of local public interest, updated weekly.

Snowpack at McClure Pass reaches 144% of average

Snowpack in the Roaring Fork basin reached 120% of average on March 5 or 129% of median with 17.6 inches of snow-water equivalent, according to NOAA.

SNOTEL sites that monitor snowfall throughout the winter measured the snowpack at Independence Pass at 97% of average on March 5 with a “snow water equivalent” (SWE) of 13 inches, up from 12.5 inches on Feb. 26. Last year on March 5, the SNOTEL station up the pass (located at elevation 10,600 feet) recorded an SWE of 11.3 inches.

The monitoring station at McClure Pass located at elevation 8,770 feet recorded a SWE of 21.6 inches on March 5, or 144% of average. That’s up from a SWE of 19.9 inches on Feb. 26. Last year, on March 5, the station measured a snowpack holding 11.9 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 13.7 inches of SWE on Feb. 26, or 108.7% of average.

Snowpack at Schofield Pass reached 34.6 inches on Feb. 26, which represents 123.6% of average. 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.

Air temperatures keep swinging

High air temperatures at the Aspen airport increased from 25°F on Feb. 23 to 46°F on Feb. 25 before dropping to 27°F on Feb. 28, which is about 11 degrees below normal. Meanwhile, low temperatures increased from 14°F on Feb. 20 to 21°F on Feb. 26 before going down to 7°F on Feb. 27, which is about six degrees below normal.

Lake Powell’s elevation keeps dipping

Lake Powell‘s storage is at its lowest level recorded since it began filling in the 1960s. On March 5, the reservoir was 21.82% full (with a total capacity based on a 1986 sedimentation survey) or 22.76% full (based on updated 2017-18 sedimentation data). That’s down from Feb. 26, when the nation’s second-largest reservoir was at 21.89% of capacity (1986 data) or 22.84% (based on 2017-18 data).

On July 1, 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.

The reservoir’s capacity has fallen since last year, when on March 5, 2022, it was 24.67% full (based on 1986 data).

On March 5, Lake Powell’s elevation reached 3,520.8 feet, or 179.2 feet from full pool, down from 3,521.1 feet on Feb. 26. The reservoir’s water level on March 5 was 4.2 feet below the target elevation of 3,525. In the last water year, Powell’s surface elevation peaked at 3,539.84 feet on July 3, after it dipped to what was then its lowest level since filling of 3,522.24 on April 22. Last year, on March 5, the reservoir reached 3,526.2 feet in elevation, or 173.8 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.

Air quality remains ‘good’ in Aspen

The air quality in Aspen was “good” last week with an AQI index for ozone ranging from 42 on March 1 to 49 on Feb. 27.

Laurine Lassalle is Aspen Journalism’s data desk editor, where she works to catalogue and analyze local public data. She also heads our our “Tracking the Curve” project, documenting COVID-19 in Pitkin,...