Quantifying effective precipitation and its non-stationarity to improve drought assessments in the southeastern united states the southeastern US (SE) faces significant challenges from droughts,…

The National Oceanic and Atmospheric Administration awarded a $496,422 cooperative agreement to The University of Alabama in Huntsville on July 1, 2026, under the Climate and Atmospheric Research program (CFDA 11.431) to develop an improved operational drought index for the Southeastern United States.

The project delivers a modified Standardized Precipitation Index (SPIE) that incorporates effective precipitation—the fraction of rainfall absorbed into soil and available for long-term storage—to address limitations in traditional drought metrics that underestimate severity in the region. The recipient will collect observed soil moisture and precipitation data across multiple regional networks to quantify how changes in precipitation patterns are driving non-stationarity in drought dynamics, then produce a near-real-time operational drought assessment product hosted on platforms including the Southern Regional Climate Centers Water Portal and Drought.gov. The work addresses the Southeastern U.S. challenge of rapid water loss through surface runoff during intense storms despite substantial annual precipitation, and responds to climate model projections of greater rainfall variability and intensity in the region.

Performance takes place in Huntsville, Alabama, with a completion date of June 30, 2028. The project includes formation of a Southeastern Regional Working Group to support decision-making in agriculture, water management, and climate adaptation.

Quantifying effective precipitation and its non-stationarity to improve drought assessments in the southeastern united states the southeastern US (SE) faces significant challenges from droughts, exacerbated by unique hydrological and climatic conditions. Despite substantial annual precipitation, the region experiences rapid water loss through surface runoff during intense storms, preventing water from being absorbed into the soil and limiting long-term soil moisture retention. Climate models indicate that the SE will continue to experience greater variability in rainfall intensity and distribution, driven by warming atmospheric temperatures. Traditional drought metrics fail to fully capture these dynamics, often underestimating drought severity. This proposal introduces an effective precipitation (PE) metric, which accounts for precipitation that is absorbed into the soil and available for long-term storage, offering a more realistic measure of drought conditions. This project will develop an improved operational drought index based on PE providing real-time, actionable drought assessments for the southeastern U.S. (SE) to enhance decision-making in agriculture, water management, and climate adaptation. By accounting for PE will are addressing a key process driving non-stationarity in the SE, rainfall intensity. Through the collection of observed soil moisture and precipitation data across multiple regional networks, the project will assess and quantify the non-stationarity of PE by assessing how changes in precipitation patterns are affecting drought dynamics. We will develop a modified SPI index (spie) that incorporates PE and compare IT to traditional drought indices. The resulting operational product will provide near-real-time drought assessments, which will be hosted on platforms like the southern regional climate centers water portal and drought.GOV. Central to this project is the formation of a southeastern regional working group, consisting of state climate offices, regional stakeholders, and drought monitoring experts. The working group will provide critical feedback throughout the projects development, ensuring that the tools are relevant, practical, and integrated into existing drought monitoring systems such as the southeastern drought early warning system (SE dews). By hosting two regional workshops, this collaboration will guide the creation of a real-time operational product that can be used for immediate drought assessment and forecasting. The project will improve drought forecasting, enhance water resource management, and increase climate resilience, particularly for those most vulnerable to drought impacts. Additionally, the tools and data developed will be made accessible to underserved communities, ensuring that all stakeholders have the information needed to manage drought risks effectively. This research aligns with noaas long-term climate goals by improving operational drought monitoring, enhancing drought indicator performance, and addressing regional climate shifts and drought variability in a changing climate.