We examine the use of El Nino-Southern Oscillation (ENSO) forecasts for flood planning in the Pacific Northwest. Using theories of resource mobilization as a conceptual foundation, the paper relies on: 1) case studies of three communities vulnerable to flooding that have had access to long-term forecasts of ENSO conditions; and 2) analysis of data collected from a survey of nearly 60 local emergency managers, planners, and public works staff. We find that understanding the regulatory machinery and other institutions involved in using climate forecasts is critical to more effective use of these forecasts. Forecast use could be promoted by: 1) an extension service to broker climate information; 2) the identification or creation of federal authorities to fund activities to mitigate ENSO impacts; and 3) the proactive use of ENSO signals to identify areas most likely to be influenced by climate anomalies.