Smith et al. (2026) Improved seasonal hydrological forecasting for Great Britain

Identification

• Journal: Hydrology and earth system sciences
• Year: 2026
• Date: 2026-10-05
• Authors: M. Smith, Victoria A. Bell, Nicky Stringer, Helen Elizabeth Baron, Helen Davies, Jeff R Knight
• DOI: 10.5194/hess-30-6189-2026

Research Groups

• UK Centre for Ecology and Hydrology (UKCEH)
• Hadley Centre, Met Office
• British Geological Survey (BGS)

Short Summary

This study evaluates the use of high-resolution seasonal rainfall forecasts derived from Historic Weather Analogues (HWA) in a national-scale hydrological forecasting scheme for Great Britain. The results show that HWA rainfall forecasts perform better than GloSea5 forecasts and improve the skill of river flow forecasts, particularly in winter.

Objective

• To evaluate the performance of HWA rainfall forecasts in a national-scale hydrological forecasting scheme for Great Britain.
• To assess the impact of HWA rainfall forecasts on the skill of river flow forecasts.

Study Configuration

• Spatial Scale: 1 km resolution across Great Britain.
• Temporal Scale: Seasonal (3 months) and monthly forecasts.

Methodology and Data

• Models used: GloSea6, G2G/WBM hydrological model, Historic Weather Analogues (HWA) rainfall forecasting approach.
• Data sources: HadUK-Grid dataset for rainfall observations, MORECS data for potential evaporation.

Main Results

• HWA rainfall forecasts perform better than GloSea5 forecasts in winter and spring.
• River flow forecasts driven by HWA rainfall forecasts show improved skill compared to GloSea5-driven forecasts.
• The skill of river flow forecasts is highest in winter and lowest in summer.

Contributions

• This study demonstrates the potential of HWA rainfall forecasting approach for improving seasonal hydrological forecasting in Great Britain.
• The results highlight the importance of high-resolution rainfall forecasts for improving the skill of river flow forecasts.

Funding

• UK Centre for Ecology and Hydrology (UKCEH) funded this research through various projects, including the HydroSOS project.

Citation

@article{Smith2026Improved,
  author = {Smith, M. and Bell, Victoria A. and Stringer, Nicky and Baron, Helen Elizabeth and Davies, Helen and Knight, Jeff R},
  title = {Improved seasonal hydrological forecasting for Great Britain},
  journal = {Hydrology and earth system sciences},
  year = {2026},
  doi = {10.5194/hess-30-6189-2026},
  url = {https://doi.org/10.5194/hess-30-6189-2026}
}