Development of National Weather Service Probabilistic Drought Outlooks

Each month, the National Weather Service issues monthly and seasonal U.S. drought outlooks. These forecasts support drought decision making and situational awareness for national, regional, and state governments and other stakeholders. The outlooks primarily support the agriculture, water resources, fire weather, and emergency management communities. 

The current drought outlook maps highlight the change in drought category from the start to the end of the forecast period. These outlooks are deterministic, meaning they provide a single, direct forecast of future drought conditions—such as whether conditions will improve, persist, or worsen—based on expert forecaster assessment rather than a range of statistical probabilities. For many years, users have requested probabilistic drought outlooks similar to other existing National Weather Service products, which would provide greater context on possible drought outcomes to inform decision-making. 

The goal of this project is to develop a probabilistic flash drought outlook, monthly drought outlook, and seasonal drought outlook. CPC will base the development of these probabilistic drought outlooks on dynamical subseasonal and seasonal forecasts, and incorporate supplemental statistical prediction tools as appropriate. 

This task involves substantial development work. To date, National Weather Service forecasters have developed an experimental probabilistic drought outlook framework, as well as a probabilistic seasonal drought outlook. National Weather Service forecasters are already integrating the probabilistic seasonal drought outlook into their current drought outlook processes. The team is currently developing a probabilistic flash drought outlook and monthly drought outlook. They also plan to expand the new outlooks beyond the contiguous U.S. to Alaska and Hawaii

This work is part of a broader NIDIS-supported research effort to improve NOAA National Weather Service drought outlooks. For more information, please contact Amanda Sheffield (amanda.sheffield@noaa.gov).