In support of the Climate Assessment Project for the Southwest, a review was conducted of the current state of weather, climate, and hydrologic forecasting for the Southwest. A key element of the review was a workshop that examined the availability, use, accuracy, and value of forecasts, with participants consisting primarily of agency personnel involved in operational forecasting via directly issuing forecasts, providing key data for making forecasts, or serving as a key link for communicating forecasts. The broad range of forecast products encompasses myriad variables, time-scales from minutes to seasons, and lead-times from minutes to over a year. Current forecast products and techniques are reviewed, and implications for use in decision making are discussed. The forecast review identified needs for additional research to be addressed by the CLIMAS Project, including local evaluation of monthly and seasonal climate outlooks, retrospective evaluation of operational water supply outlooks, hindcast reanalysis of probabilistic water supply outlook techniques, and incorporation of climate outlooks into statistical water supply outlook techniques.

Research into the sensitivity and vulnerability of urban water systems in Arizona reveals that managers are more concerned about factors such as population growth projections, economic trends, and revenue flows. Reliance on groundwater resources in many cases obscures recognition of any direct impact of precipitation on water supply. Given the low level of perceived climate risk among many providers interviewed for this study, it would seem unlikely that climate information would be needed. However, pockets of sensitivity and vulnerability to climatic impacts do exist in the four study areas covered in this study.