Articles | Volume 30, issue 14
https://doi.org/10.5194/hess-30-4457-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/hess-30-4457-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Capturing the extremes: a quasi-comonotonicity-based algorithm for disaggregating daily to hourly rainfall
Spanish Meteorological Agency (AEMET), Madrid, 28040, Spain
Alfonso Hernanz
Spanish Meteorological Agency (AEMET), Madrid, 28040, Spain
Iván San-Felipe
Spanish Meteorological Agency (AEMET), Madrid, 28040, Spain
Esteban Rodríguez-Guisado
Spanish Meteorological Agency (AEMET), Madrid, 28040, Spain
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We explore how deep learning can improve local climate projections by adapting a national model to regional data. By relying on a paradigm called pre-training, we show that models can produce more consistent and physically aligned results, even when data is limited. This helps make future climate projections more reliable and supports better planning at both national and local levels.
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This study compares observed and simulated rainfall in a mountainous area in central Spain from 1991 to 2020. It uses data from high and low elevations, along with long-term simulations and tests at very fine detail. While the finest detail tends to overestimate rainy days, it better captures heavy rainfall events. Overall, the results improve understanding of rainfall patterns and the benefits of higher detail.
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We propose a statistical technique for the construction of targeted teleconnection patterns, which maximizes the predictability of a user-selected impact variable in terms of large-scale atmospheric circulation. The implementation of targeted teleconnections into the statistical postprocessing of climate predictions can considerably increase the forecast skill compared to postprocessing based on EOF modes of variability.
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There has been developed for Central America downscaled climate change scenarios using the same methodology, that allows a joint analysis for the whole region. The high number of simulations improves the situation prior to the start of the action, where each country had a limited number of projections that differed in terms of background information, methodology and resolution. A web based viewer allows consultations and download on 37 different climatic variables and derived indices.
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Short summary
Heavy rainfall over short periods can cause floods and damage in cities, yet rainfall is often only measured daily. We developed a new method to generate realistic hourly rainfall data from daily values, using information from many weather stations in Spain and the United States. Our approach reproduces extreme rainfall more accurately than existing methods, helping to improve flood risk studies, infrastructure design, and climate impact assessments.
Heavy rainfall over short periods can cause floods and damage in cities, yet rainfall is often...