Drought

Drought occurs when an extended imbalance between water supply (precipitation) and water loss (evapotranspiration and/or human use) leads to an abnormal water deficit in critical hydrological components such as soils, streams, and reservoirs.

Drought poses a significant threat to the security and prosperity of the United States, both domestically and internationally, with far reaching consequences that include, but are not limited to:

• decreased agricultural yields;
• reduced water availability for consumption;
• hindered transportation such as low waterway levels and road/rail destablization; and
• wildfires.

These effects can make food and water insecurity worse, potentially leading to societal unrest (Kelley et al., 2026; Voice of America, 2011). The consequences are also financial. Between 1980 and 2024, drought-related economic losses in the U.S. amounted to nearly $370 billion (per National Centers for Environmental Information).

By conducting dedicated research, developing advanced predictive tools, and delivering key insights, PSL helps key community decision makers and local, state, and federal partners better anticipate and manage the effects of drought.

Initiatives and partnerships

PSL develops and improves on the evidence and delivery of early warning of drought and its compounding and cascading effects through impactful initiatives and partnerships.

Modernizing Drought Early Warning in the United States - Pilot Program

PSL leads an experimental drought resilience framework to produce sector-specific drought scenarios based on tailored monitoring and forecasting information, which will enable users to make proactive decisions ahead of drought. These sectors include water utilities, public health, and agriculture.

This pilot is being conducted in partnership with NOAA’s National Integrated Drought Information System, the California State Climatologist/California Department of Water Resources, NOAA’s National Weather Service and National Centers for Environmental Information, and the California-Nevada Adaptation Program (a NOAA CAP team)

Together the team delivers a user-oriented and evidence-based approach to drought early warning for sectors of our Nation’s economy susceptible to the hazards of too much and too little water.

Famine Early Warning Systems Network (FEWS NET)

PSL leads the development of acute food insecurity scenarios based on current and evolving drought conditions in over 40 countries worldwide for the Department of State Famine Early Warning Systems Network. These scenarios inform decisions and responses in the world’s most food-insecure countries, including more accurate estimates of food aid.

Experimental monitoring and forecasting products

The following experimental tools provide important data and visualizations to support the early warning of drought and its compounding and cascading effects.

Recent research and analysis

Weather whiplash in Texas: drought to flood
PSL researchers analyzed the extreme transition from drought to flood in central Texas in early July 2025 to improve understanding of "weather whiplash" extremes and advance early warning and planning.

Seasonal Predictability of Vapor Pressure Deficit in the western United States
As wildfire seasons grow longer, knowing what lies ahead is critical. This paper explains how vapor pressure deficit (VPD) can be forecasted months ahead of time, potentially giving fire managers a critical head start on resource planning. These forecasts are generated using a machine learning approach with a linear inverse model.
See citation

Using Deep Learning to Identify Initial Error Sensitivity for Interpretable ENSO Forecasts
Better drought prediction starts with better ENSO forecasting. This study unveils a 'glass box' AI approach that doesn’t just predict El Niño and La Niña with high accuracy—it actually reveals the hidden ocean and wind patterns that drive them, offering a major leap forward for regional climate preparedness.
See citation

Potential Predictability of Two-Year Droughts in the Missouri River Basin
Predicting a single dry summer is hard enough; predicting two in a row is even harder. This study identifies the specific 'March precursors'—including soil moisture and La Niña—that signal a high risk of 2-year droughts in the vital Missouri River Basin.
See citation

Flash drought: A state of the science review
A 'Flash drought' involves rapid onset, no warning, and severe impacts. This state-of-the-science review unifies the science behind these fast-moving climate events that have a significant effect on water security.
See citation

Rapid Development of Systematic ENSO-Related Seasonal Forecast Errors
El Niño models contain immediate, critical forecasting errors in the tropical Pacific, driven by the atmosphere rather than the ocean. This "westward shift" in simulated temperatures is a key factor limiting accurate worldwide seasonal weather prediction.
See citation