Snow water equivalent (SWE)
The amount of water contained in a snowpack — how much you would get if it melted right now.
Snow depth is a poor predictor of water; density varies enormously between a dry January storm and a wet spring one. SWE measures the thing that actually matters, and automated SNOTEL stations report it daily across western mountain ranges.
Because most western runoff begins as snow, SWE in March is a usable forecast of July supply. It is the earliest credible signal available and it arrives months before anyone has to make a curtailment decision.
Where this shows up in the data
Who this matters to
See also
More in Hydrology & supply
Stop reading definitions. Look at the data.
2.1M+ water rights, 26 layers and 17 states. Free to start.
Create a free account