Spatio-temporal precipitation downscaling at hourly resolution based on km-scale regional simulations
Abstract
Effectively preparing for changes in extreme flooding requires understanding present and future rainfall extremes with return periods up to ∼100-1000 years, including changes in intensity, spatial structure at km-scale and sub-daily temporal variability. Conventional km-scale climate models give greatly increased realism compared to typical global climate models (GCMs) but are too computationally costly to allow enough simulations for robustly quantifying changes in extremes. This work presents an approach based on video diffusion to generate realistic precipitation at 8.8km-hourly resolution by spatially and temporally downscaling daily, GCM-scale atmospheric variables. The emulator is trained to produce similar output to a 4×-coarsening of the Met Office's 2.2km-resolution UK convection-permitting model. An application for such an emulator is to downscale large-ensemble GCM simulations to allow quantification of ∼100-1000-year return level rainfall, which in turn can be used to drive hydrological and flood models for improved projections of future changes in flood risk.
Related
- Dependence of the precipitation intensity distribution on spatial and temporal resolution in observations
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- Stress-Testing Dynamical and Generative Downscaling Using Subseasonal Extreme Precipitation Forecasts
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BibTeX
@misc{addison2026spatiotemporal,
title = {{Spatio-temporal precipitation downscaling at hourly resolution based on km-scale regional simulations}},
author = {Henry Addison and Elizabeth J. Kendon and Peter A. G. Watson},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.26145},
eprint = {2610.26145},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.26145},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Spatio-temporal precipitation downscaling at hourly resolution based on km-scale regional simulations
AU - Henry Addison
AU - Elizabeth J. Kendon
AU - Peter A. G. Watson
PY - 2026
DA - 2026/10/19
PB - arXiv
DO - 10.48550/arxiv.2610.26145
UR - https://arxiv.org/abs/2610.26145
AB - Effectively preparing for changes in extreme flooding requires understanding present and future rainfall extremes with return periods up to ∼100-1000 years, including changes in intensity, spatial structure at km-scale and sub-daily temporal variability. Conventional km-scale climate models give greatly increased realism compared to typical global climate models (GCMs) but are too computationally costly to allow enough simulations for robustly quantifying changes in extremes. This work presents an approach based on video diffusion to generate realistic precipitation at 8.8km-hourly resolution by spatially and temporally downscaling daily, GCM-scale atmospheric variables. The emulator is trained to produce similar output to a 4×-coarsening of the Met Office's 2.2km-resolution UK convection-permitting model. An application for such an emulator is to downscale large-ensemble GCM simulations to allow quantification of ∼100-1000-year return level rainfall, which in turn can be used to drive hydrological and flood models for improved projections of future changes in flood risk.
ER -