Northern Water published its April streamflow forecast today. We expect the flows to be even higher than what we projected a month ago - so high that some of us are using words like "epic" to describe the West Slope snowpack.
Many of our forecasting tools are struggling because of a lack of a key type of data: comparable years. Our forecasters look at similar water years to estimate what kind of runoff to expect, and for many of the basins Northern Water monitors, we have less than a handful of "comparables" available to analyze.
For example, Willow Creek only has one year on SNOTEL record that compares to this year: 1986. That year the seasonal runoff (April through July) on Willow Creek was 85,600 acre feet - 170 percent of average. This year we're not far behind with an anticipated runoff that's 160 percent of average.
The Colorado River Basin Forecast Center has a nice tool for following this year's snowpack and how it matches up to 1986. We're less than an inch away from a record snowpack for Willow Creek ... and the National Weather Service is calling for more snow later this week!
