This chart compares the annual peak modeled snow water in the Upper Colorado basin against Lake Powell’s April 1 to July 31 unregulated inflow. It treats the SNODAS peak as the basin-wide snow supply signal, and the Apr 1 to Jul 31 total as the main runoff-season response at Powell.
How to use this chart
Each dot is one water year. The x-axis is the peak Upper Colorado SNODAS snow water for that year, and the y-axis is total April 1 to July 31 unregulated inflow to Lake Powell in million acre-feet. Hover any point to inspect the year, the SNODAS peak date and value, and the matching Apr 1 to Jul 31 inflow total.
Years are only included when both conditions are met:
- local SNODAS coverage reaches at least
May 1, so the seasonal peak is likely represented - Lake Powell has a complete
Apr 1throughJul 31unregulated inflow total for that water year
Upper Colorado SNODAS Peak vs Apr 1 to Jul 31 Unregulated Inflow
Data Sources
- Local derived join of Upper Colorado water-year SNODAS packs and Lake Powell water-year inflow totals.1
- Local Upper Colorado SNODAS water-year summaries, built from NOAA / NSIDC SNODAS daily archive coverage.23
- Local Lake Powell water-year file derived from USBR Hydrodata daily series.4
- 1
Derived local join file - upper-colorado-snodas-peak-vs-apr-jul-unregulated-inflow.json. ↩︎
- 2
Example Upper Colorado SNODAS water-year summary - upper-colorado-wy2025.json. ↩︎
- 3
NOAA@NSIDC SNODAS masked archive - 2025 daily archive directory. ↩︎
- 4
Local Lake Powell water-year dataset - lake-powell-water-year.json. ↩︎