Employing Multiple Drought Indices for Global Decision Support

The 14th Weather Squadron is the U.S. military organization responsible for delivering climate information and services to entities of the Department of Defense and within portions of the National Intelligence Community and Department of State. Water resource insecurity has driven societal distress and conflict throughout history. Therefore, both the characterization and anticipation of drought conditions are key to providing actionable environmental intelligence to a range of decision makers. Until recently, the 14th Weather Squadron relied almost exclusively on the Standard Precipitation Index (SPI) to monitor and analyze drought conditions. The SPI is also used in a novel approach to anticipate drought conditions across the subseasonal-to-seasonal time scale. Here, we highlight recent real-world cases when the SPI used alone poorly distinguished consequential drought and/or water stress conditions. We demonstrate how the deliberate exploitation of multiple drought indices across various time scales produces a more robust and durable drought characterization for global decision support activities.