Much of the Yampa River Basin is currently a snowmelt-driven system, meaning that the majority of river flows are derived from a melting snowpack in the springtime (as opposed to rainfall or groundwater). In a snowmelt-driven system, snowpack characteristics have a direct effect on the basin’s overall flow regime.

This indicator considers how certain snowpack characteristics differ from the historical average. Snowpack characteristics considered include: maximum snowpack depth and associated maximum snow-water equivalent (SWE) volume, timing of maximum snowpack, and timing from maximum snowpack to peak runoff.