This month’s US Bureau of Reclamation reservoir forecast model runs show the implications of the warm, dry spring, with a drop of 620,000 acre feet and six feet in elevation in the estimated end-of-year storage in Lake Powell, the major reservoir in the Upper Colorado River Basin. Here’s my long term forecast graph, updated with …

Continue reading ‘The warm, dry spring pushing Colorado River reservoir forecast levels down’ »

Connie Woodhouse at the University of Arizona and colleagues have a new paper presenting the most direct link yet between a greenhouse-warmed climate and reduced flows in the Colorado River. Modeling has for many years projected such an effect in the future, but the new Woodhouse et al. paper (Increasing influence of air temperature on …

Continue reading ‘New evidence that a warming climate is already reducing Colorado River flows’ »

Via the Colorado Basin River Forecast Center, here’s the February precipitation to date in the parts of the basin that make snow and therefore water: Beyond the dry, this map does a good job of how tenuously tiny an area produces the river’s water supply.

In my endless puzzling over the meanings we attach to the word “drought”, there is this, from yesterday’s Climate Prediction Center seasonal drought outlook: What does it mean to talk about “drought” in places like Yuma or the Imperial Valley that average less than 4 inches (10 cm) of rain a year, and that get …

Continue reading ‘What does it mean to have “drought” in Yuma?’ »

It was 72F (22C) in Albuquerque yesterday, a record, and our decent snowpack is already starting to melt out. It’s early for that. And February (see PRISM map at right) has been dry, which hasn’t helped. In the Upper Colorado River Basin, snowpack measured across all the river’s main tributary systems above Lake Powell (the …

Continue reading ‘Awaiting our May miracle in the Colorado River Basin’ »

With the current snowpack in the Colorado Basin watersheds above Lake Powell at 93 percent of average (source: CBRFC), we’re entering the critical time for the 2015-16 water year on the Colorado River. Today’s forecast from the federal government’s Climate Prediction Center has the odds tipped toward a wet later winter and spring, but not …

Continue reading ‘Odds favor wet late winter, spring across Colorado River Basin’ »