Challenges in Forecasting the 2011 Runoff Season in the Colorado Basin

Historically large snowpack across the upper Colorado basin and the Great Basin in 2011 presented the potential for widespread and severe flooding. While widespread flooding did occur, its impacts were largely moderated through a combination of sustained cool weather during the melt season and mitigation measures based on forecasts. The potential for more severe flooding persisted from April through the first part of July as record-high snowpacks slowly melted. NOAA's Colorado Basin River Forecast Center (CBRFC) is the primary office responsible for generating river forecasts in support of emergency and water management within the Colorado River basin. This paper describes the 2011 runoff season in the basin and examines the skill of CBRFC forecasts for that season. The primary goal of this paper is to raise awareness of the research and development areas that could, if successfully integrated into the CBRFC river forecasting system, improve forecasts in similar situations in the future. The authors identify three areas of potential forecast improvement: 1) improving week two to seasonal weather and climate predictions, 2) incorporation of remotely sensed snow-covered area, and 3) improving coordination between reservoir operations and forecasts.