Li et al. (2026) Assessing Subseasonal Predictability and Sources of Drought‐Flood Abrupt Alternation Over Eastern China Using ECMWF S2S Ensemble Forecasts

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Journal of Geophysical Research Atmospheres
• Year: 2026
• Date: 2026-10-01
• Authors: Chunxiang Li, Wansuo Duan, Zhe Han
• DOI: 10.1029/2026jd046625

Research Groups

• Institute of Atmospheric Physics, Chinese Academy of Sciences
• ECMWF (European Centre for Medium-Range Weather Forecasts)

Short Summary

This study investigates the subseasonal predictability of drought-flood abrupt alternation events over eastern China using ECMWF S2S ensemble forecasts. The results highlight the importance of large-scale circulation precursors in predicting such events.

Objective

• Investigate the subseasonal predictability of DFAA events over eastern China during 2022–2024

Study Configuration

• Spatial Scale: Eastern China, with a focus on the region's hydrological transitions and complex circulation controls.
• Temporal Scale: Subseasonal-to-seasonal (S2S) prediction, with a focus on predicting drought-flood abrupt alternation events.

Methodology and Data

• Models used: ECMWF S2S ensemble forecasts
• Data sources: Ensemble forecast data from ECMWF

Main Results

• Forecast skill tends to be higher during the drought phase than during the subsequent transition and flood onset.
• Persistent drought conditions are linked to slowly evolving, spatially coherent large-scale circulation anomalies.
• Mid-tropospheric circulation anomalies, including Rossby wave trains and subtropical-midlatitude coupling, provide coherent precursor signals approximately 10–30 days prior to the observed transitions.

Contributions

• This study highlights the importance of large-scale circulation precursors for extended-range monitoring of DFAA events, underscoring the limitations of current S2S systems in predicting the precise timing and intensity of abrupt flooding onset.

Funding

• Not specified in the paper.

Citation

@article{Li2026Assessing,
  author = {Li, Chunxiang and Duan, Wansuo and Han, Zhe},
  title = {Assessing Subseasonal Predictability and Sources of Drought‐Flood Abrupt Alternation Over Eastern China Using ECMWF S2S Ensemble Forecasts},
  journal = {Journal of Geophysical Research Atmospheres},
  year = {2026},
  doi = {10.1029/2026jd046625},
  url = {https://doi.org/10.1029/2026jd046625}
}