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Sep 22 pass · published Sep 26Sign in

Ptarmigan Glacier

40.3125, −105.6996 · 3,587 m · NNE · 23° · 0.6 ha on Sep 22

Snow · small

From the satellite, Sep 22 pass. No ground report in the last 10 days.

See what we saw

Drag the handle to compare two passes. The blue line is what the scanner counted as snow.

A · JUL 14 · CLEAR · 4.9 HAB · SEP 22 · CLEAR · 0.6 HA
0    200 m
N
Every pass this season · pick A and B

Sentinel-2 L2A true color, read at 20 m. One pixel is 0.04 ha. A strip narrower than about 40 m can hold skiable snow and show nothing. By mid-September, north-facing cirques sit in shadow at the late-morning overpass, so one zero isn't proof of anything.

How we got to this status

  1. The Sep 24 pass was cloudy over the site (100%), so a cloudy pass counts as no look, not as zero. This uses the Sep 22 pass.
  2. Sep 22 pass fully covers the site and is clear over it.
  3. 15 snow pixels in 2 clusters, which is 0.6 ha.
  4. Not flagged as possible new snow.
  5. Under 1 ha, so it's marked Small.
Scan run 1 · status rules 2026.09-2
NDSI > 0.4 · NIR ≥ 0.6 × green · SCL mask · algorithm 2026.09-2

Getting there

Approach
~3.5 h · 6 km one way
Route
Bear Lake TH, via Flattop Mountain trail; the glacier sits just north of the summit plateau
Estimate
Munter rule from straight-line distance and climb. Rough.

Snow on each pass

Hectares of counted snow. Grey stubs are passes with cloud over the site.
0 ha12345JUL 4: cloud or not coveredJUL 9: cloud or not coveredJUL 14: 4.92 haJUL 19: cloud or not coveredJUL 24: 1.88 hashadow?JUL 26: 3.16 haJUL 29: 2.92 haAUG 3: 2.32 haAUG 8: cloud or not coveredAUG 13: cloud or not coveredAUG 15: cloud or not coveredAUG 18: cloud or not coveredAUG 23: cloud or not coveredAUG 28: 0.04 haSEP 2: 0 hashadow?SEP 4: 0.4 haSEP 7: cloud or not coveredSEP 12: cloud or not coveredSEP 17: cloud or not coveredSEP 22: 0.6 haSEP 24: cloud or not coveredJUL 4JUL 19JUL 29AUG 13AUG 23SEP 4SEP 17SEP 24PA · SEP 24

From the ground

Visible bright patch just north of Tyndall.

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