Now this is getting interesting… Usually our western mountain snowpack reaches its peak Snow Water Equivalent (SWE) in early April – not this year the pack peaked in mid-March under the early season Heat Dome. And now some of the rivers have also seen their snowmelt runoff peak. Seems like the snow and flow cycles are 2-3-4 weeks ahead of normal primarily from those warm temps. The Owhyee forgot to peak this year and is flowing at record lows levels very similar to 1992. The Bruneau rose last week and time will tell if there’s another snow increase.

An interesting observation in the Salmon and Selway basins is how much snow melted to provide March flows. This snowmelt was not just from mid-elevations but also higher elevations that are melting. So considering most of the streamflow volume forecasts are for the April-July period, does this shift of runoff into March mean the observed April-July volumes will be less and low summer base flows will occur even early this year. Is it time to consider shifting the primary forecast period from April-July to March-July?

This week’s last winter storm is just what is needed to slow the melt, add a little moisture to the pack, and rain on the soils as the snow melts. A cool wet spring would be ideal along with spring storms. Remember Yellowstone June 2022 and June 1963 Owyhee rain event pushed the river up to 5000 cfs. The least we need is another near record dry April-May-June precipitation like we saw last spring.