a lousy monsoon

soil moisture heading into the 2020 runoff, courtesy CBRFC

Despite an above-average snowpack in significant parts of the Colorado River Basin, the initial 2020 forecast is for below-average runoff thanks to a dry summer and fall.

According to the Colorado River Basin Forecast Center’s Cody Moser, speaking in today’s first-of-2020 forecast briefings, the monsoon over the Colorado River Basin was the 9th driest and 3rd hottest in a record that goes back to 1895. That means very dry soil moisture heading into the snow season. And that dry soil must then soak up the first pulse of melt before water can get to the rivers.

With three months of snow season to go, the error bars are still huge, with a forecast mean flow into Lake Powell of 82 percent. Pictures here courtesy CBRFC, click for more forecast maps and information than you could every think of asking for.