KNOW YOUR STREAMFLOW: Snowpack’s importance to streamflow

When snowpack – the snow that accumulates on the ground – melts into liquid water, it supplies much of the streamflow in streams and rivers. This is especially important in a mountainous watershed like the Uncompahgre. Snowpack varies considerably over time and space according to local conditions like air temperature, relative humidity, wind, slope, and sun exposure. It is also affected by the characteristics of the snow like reflection (called “albedo”) and density.

In the satellite image below, snowpack is indicated as depth in inches for the central Rockies, including western Colorado. Source: NOAA

NOAA satellite image about snow depth on Red Mountain, Colorado on March 1, 2024

Have you seen the term “SWE” in snow forecasts and reports?

SWE is the acronym for snow water equivalent, a commonly used indicator of snowpack contribution to runoff and streamflow. SWE is the amount of water held within the snowpack at a particular location. It consists of the depth of water that results when the snowpack completely melts.

Please remember to enter the Uncompahgre River Classic peak flow prediction contest by May 1 (for free)! You could win great Patagonia gear and bragging rights as the most drip streamflow forecaster of the year.