SNOWLINE DATA CATALOG

Complete satellite imagery and SNOTEL station data for SW Montana
← Back to Map
SNOTEL Stations
Satellite Coverage

Satellite Imagery Availability

Every satellite pass over SW Montana — clear days, cloudy days, and everything in between. We query four collections on Microsoft's Planetary Computer: Sentinel-2 L2A (10m, native), Landsat 8/9 C2 (30m), and the harmonized HLS-S30 + HLS-L30 (30m). HLS is often fresher than the native collections because Microsoft sometimes lags ingesting new scenes. AOI: -112.2, 44.9 to -109.0, 46.5 — 12 Sentinel-2 tiles for full coverage. The "Why" column explains what each pass means in plain English.
Show:
All Passes
Excellent
Good+
Usable (any)
Cloudy Only
Loading satellite data...

Sentinel-2 Passes

Every Sentinel-2 pass over the AOI. One row per date. The "Products Available" column shows which processed versions exist: L2A = native Sentinel-2 L2A (10m, ESA's processor) or HLS-S30 = NASA's harmonized 30m product. These are not two separate passes — they're the same observation processed differently. We query both because Microsoft sometimes ingests HLS faster than native L2A.
Loading…

Landsat Passes

Every Landsat 8/9 pass over the AOI. One row per date. L2-C2 = native Landsat Collection 2 L2 (30m) and HLS-L30 = NASA's harmonized version of the same observation. Landsat has a 16-day revisit per satellite, ~8 days combined for L8+L9.
Loading…

SNOTEL Station Data

NRCS SNOTEL ground measurement stations. All data from NRCS AWDB API (free). Dashed line = 20-year median. Click any station or range to expand.

Basin-Wide Season Snow Depth

Loading all stations...

Snow Distribution Across Stations

Each SNOTEL station colored by its current snow depth as a percentage of today's regional maximum. Blue dots = the highest-snow stations right now. Red dots = the lowest. Hover for details, click to jump to that station's chart below.
Lowest
Highest (regional max today)

By Mountain Range

Individual Stations

Loading SNOTEL data...