From Snow to Flow: Estimating the Timing of Peak Streamflow from SNOTEL Ablation Curves

Predictions of peak streamflow timing in snow-dominated river systems are essential for proper water management and recreational availability. This study evaluates historic snow and streamflow data from 11 river basins throughout Idaho to investigate the relationship between snowmelt at SNOw TELemetry (SNOTEL) sites and peak streamflow within each basin. The goal is to provide a simple predictive tool that estimates the probability of peak streamflow occurring within a certain number of days as ablation progresses from 0 to 100%. For individual basins we evaluate melt-out levels in increments of 10% from each SNOTEL site and use a probabilistic modeling approach to develop cumulative distribution function (CDF) curves which illustrate the probability of peak streamflow occurring within a given number of days from the date at which the SNOTEL site reaches each melt-out level. Results from the CDF curves also provide anecdotal indices of peak streamflow timing.