EGU22-10481, updated on 19 Apr 2024
EGU General Assembly 2022
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Improving early warning of droughts near onset and middle of a growing season

Shraddhanand Shukla1, William Turner1, Greg Husak1, Daniel McEvoy2, Seydou Tinni3, Adoum Alkhalil3,6, Abdou Ali3, Bako Mamne3, Ibrah Sanda3, Kathryn Grace4, Emil Cherrington5,7, and Rebekke Muench5,7
Shraddhanand Shukla et al.
  • 1University of California, Santa Barbara, Department of Geography, Santa Barbara, United States of America (
  • 2Desert Research Institute , Western Regional Climate Center, Reno, Nevada, USA.
  • 3AGRHYMET Regional Center, Niamey, Niger, USA.
  • 4Department of Geography, Environment, and Society and Minnesota Population Center University of Minnesota, Twin Cities, USA.
  • 5University of Alabama in Huntsville, Huntsville, AL
  • 6Famine Early Warning System Network Team, Washington D.C., USA

Early warning of drought is crucial for mitigation of the most adverse impacts of water and food insecurity to lives and livelihoods. Recent advances in routine production (i.e., weekly) and open access to NMME SubX—subseasonal climate forecasts—provide an unprecedented opportunity to improve drought early warning near the onset and middle of the crop-growing season. Near the onset of a season, subseasonal precipitation forecasts have the potential to provide early indication of delay in rain onset, which, as shown in a recent study (Shukla et al., 2021, PLOS ONE), can be a reliable indicator of agricultural drought development. This is particularly relevant for some of the most food-insecure regions in East Africa. Additionally, subseasonal forecasts have the potential to improve drought forecasting during the middle of the season—several months before the harvests—when they are used in combination with to-date observations. Integration of near-real-time observations with subseasonal climate forecasts can enhance drought detection capabilities by leveraging the skill that is derived from initial conditions (as of middle of the season) and complementing it with the skill of subseasonal climate forecasts. Here, we first describe how onset of the rainy season is a reliable indicator of agricultural droughts. The results indicate that in the administrative units in sub-Saharan Africa, which  have the highest risk of acute food insecurity, a delay of about 20 days in the rainy season onset can double the probability of agricultural droughts. We then describe the results of an analysis examining the performance of subseasonal climate forecasts in identifying the timing of the onset of the rainy season in those administrative units. Next, we describe a SERVIR-AST-supported project, which uses subseasonal climate forecasts to develop a West Africa-focused water-deficit forecasting system in collaboration with AGRHYMET, primarily  for agropastoral usage. Here, we make  use of a widely used crop water balance model, the Water Requirement Satisfaction Index (WRSI), to generate improved forecasts of crop water stress, and hence, crop production outcomes, during the middle of the rainy season in West Africa (June through September). We compare the performance of these forecasts with the forecasts generated using climatology only. Finally, we briefly describe how these subseasonal climate forecasting products are being disseminated, communicated, and used in the focus regions.

How to cite: Shukla, S., Turner, W., Husak, G., McEvoy, D., Tinni, S., Alkhalil, A., Ali, A., Mamne, B., Sanda, I., Grace, K., Cherrington, E., and Muench, R.: Improving early warning of droughts near onset and middle of a growing season, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10481,, 2022.


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