Sunguti et al. (2026) Robust increase in extreme future precipitation in the Lake Victoria Basin based on km-scale regional climate projections

Identification

• Journal: Journal of Climate
• Year: 2026
• Date: 2026-10-01
• Authors: Elizabeth Majani Sunguti, Jonas Van de Walle, Wim Thiery, Andreas Prein, Franklin J. Opijah, Dennis O. Ochuodho, Nicole P. M. van Lipzig
• DOI: 10.1175/jcli-d-25-0682.1

Research Groups

• Department of Earth and Environmental Sciences, KU Leuven, Leuven, Belgium
• Department of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussel, Brussels, Belgium
• ETH Zurich, Institute for Atmospheric and Climate Science, Zurich, Switzerland
• Department of Earth and Climate Sciences, University of Nairobi, Nairobi, Kenya
• Department of Biological Sciences, Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya

Short Summary

This study employs a mini-ensemble of convection-permitting pseudo-global warming regional climate simulations at 2.8 km for the Lake Victoria basin to project future extreme precipitation, revealing a robust increase in extreme precipitation despite uncertainties in mean precipitation response. The findings offer critical insights for future climate resilience planning in the region.

Objective

• To assess model uncertainties related to changes in large-scale dynamics in driving General Circulation Models (GCMs) and identify robust climate change signals for extreme precipitation in the Lake Victoria basin using a computationally efficient convection-permitting pseudo-global warming approach.

Study Configuration

• Spatial Scale: Lake Victoria basin, with a resolution of 2.8 kilometers.
• Temporal Scale: Future climate projections, using a pseudo-global warming approach to simulate future conditions, with specific analysis of diurnal cycles (e.g., 18-24 hours UTC).

Methodology and Data

• Models used: Mini-ensemble of convection-permitting pseudo-global warming (PGW) regional climate simulations.
• Data sources: Large-scale dynamics derived from driving General Circulation Models (GCMs).

Main Results

• Extreme precipitation scaling is robust across ensemble members, showing an approximate increase of 5% per Kelvin (5%/K), primarily controlled by thermodynamic processes.
• The mean precipitation response exhibits sensitivity to uncertainties in large-scale dynamics, leading to a significant spread within the ensemble.
• Projections indicate consistent drying over Lake Victoria during the 18-24 hours UTC (21-03 hours local time) period across all three ensemble members, with reductions up to -36% in the simulation experiencing the strongest decrease in easterly trade winds.
• A consistent shift is projected from low and intermediate precipitation intensities towards higher values.

Contributions

• Provides critical insights for future climate resilience planning in the Lake Victoria basin by offering high-resolution climate projections.
• Introduces a computationally efficient convection-permitting pseudo-global warming (PGW) approach, addressing resource limitations for regional climate studies, particularly in the African context.
• Identifies robust climate change signals for extreme precipitation, distinguishing them from uncertainties in mean precipitation driven by large-scale dynamics.

Funding

Not specified in the provided text.

Citation

@article{Sunguti2026Robust,
  author = {Sunguti, Elizabeth Majani and Walle, Jonas Van de and Thiery, Wim and Prein, Andreas and Opijah, Franklin J. and Ochuodho, Dennis O. and Lipzig, Nicole P. M. van},
  title = {Robust increase in extreme future precipitation in the Lake Victoria Basin based on km-scale regional climate projections},
  journal = {Journal of Climate},
  year = {2026},
  doi = {10.1175/jcli-d-25-0682.1},
  url = {https://doi.org/10.1175/jcli-d-25-0682.1}
}