Many regions in Africa and the Middle East are vulnerable to drought and to water and food insecurity, motivating agency efforts such as the U.S. Agency for International Development’s (USAID) Famine Early Warning Systems Network (FEWS NET) to provide early warning of drought events in the region. Each year these warnings guide life-saving assistance that reaches millions of people. A new NASA multimodel, remote sensing–based hydrological forecasting and analysis system, NHyFAS, has been developed to support such efforts by improving the FEWS NET’s current early warning capabilities. NHyFAS derives its skill from two sources: (i) accurate initial conditions, as produced by an offline land modeling system through the application and/or assimilation of various satellite data (precipitation, soil moisture, and terrestrial water storage), and (ii) meteorological forcing data during the forecast period as produced by a state-of-the-art ocean–land–atmosphere forecast system. The land modeling framework used is the Land Information System (LIS), which employs a suite of land surface models, allowing multimodel ensembles and multiple data assimilation strategies to better estimate land surface conditions. An evaluation of NHyFAS shows that its 1–5-month hindcasts successfully capture known historic drought events, and it has improved skill over benchmark-type hindcasts. The system also benefits from strong collaboration with end-user partners in Africa and the Middle East, who provide insights on strategies to formulate and communicate early warning indicators to water and food security communities. The additional lead time provided by this system will increase the speed, accuracy, and efficacy of humanitarian disaster relief, helping to save lives and livelihoods.

The food and water crisis that affected Zambia due to prolonged dry spells between 2018 and 2020 is an example of how natural, socioeconomic, and political drivers can produce compounding impacts with long-lasting implications for development. This retrospective disaster analysis explores the risk interactions and early warning early action functioning before and during the event, to draw lessons for anticipation and response to future crises of a similar nature. Combined, the findings feed into the understanding of risk and impacts, which is crucial for improving impact-focused early warning and implementation of early actions. The Government of Zambia’s Disaster Management and Mitigation Unity (DMMU) and Zambia Red Cross Society (ZRCS), key stakeholders in the research, indicated a gap in knowledge of the drivers and impacts of the food and water crisis in Western Province and EWEA functioning at the time, especially the more remote border areas located near the border with Angola and Namibia. No retrospective analysis of the 2018-2020 crisis event has so far included a review of the functioning of the EWEA components at the time at the national and local levels. Therefore, this analysis focuses on Western Province of Zambia, specifically the Sioma, Sesheke and Shang’ombo border districts. The research provides an in-depth perspective on one of the most recent food security crises in Zambia to inform localization and strengthen early warning and early action efforts at the national and community levels. The 2023 drought event in Zambia underscores the critical need for enhanced preparedness for similar crises. This research complements ongoing initiatives for early warning for drought (e.g. through the AWARE project) and efforts within the National Technical Working Group for Forecast-Based Financing, chaired by DMMU, on drought trigger and early action protocol development. This research's focus on hazard and vulnerability interactions aligns with the move to multi-hazard contingency planning in Zambia, led by DMMU. The mixed-methods forensic analysis builds on key informant interviews, focus group discussions, peer-reviewed literature, publicly accessible data and geospatial analysis to consider compounding and cascading risk interactions in 2018–2020 in Zambia, their attendant impacts and risk drivers, and available warnings as well as the communication and early actions associated with them. Complementing ongoing initiatives to strengthen EWEA activities in Zambia for food- and water-related impacts, this study provides contextual information that can support improved targeting, early action selection, warning system design and coordination.