Hwang et al. (2025) Large‐Scale Moisture Sources and Delivery Pathways Contributing to Winter Floods in the US

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

Identification

• Journal: Water Resources Research
• Year: 2025
• Date: 2025-11-27
• Authors: Jeongwoo Hwang, A. Sankarasubramanian
• DOI: 10.1029/2025wr040353

Research Groups

Not specified in the provided abstract.

Short Summary

This study updates previous research on US winter flood hydroclimatology by identifying large-scale moisture delivery pathways and quantifying source contributions across the Conterminous United States (CONUS). It finds that oceanic sources dominate coastal floods, while land is a key contributor to Midwest floods, influenced by moisture dynamics over mountain ranges.

Objective

• To explore the large-scale moisture delivery pathways associated with monthly floods during the winter season across the CONUS and summarize the contributions of various moisture sources for each hydrologic region (HUC02).

Study Configuration

• Spatial Scale: Conterminous United States (CONUS), analyzed at the scale of hydrologic regions (HUC02).
• Temporal Scale: Monthly floods during the winter season over an unspecified multi-year period.

Methodology and Data

• Models used: Lagrangian particle tracking model (HYSPLIT).
• Data sources: Not explicitly detailed in the provided abstract, but refers to "more extensive and longer series of data sets currently available on floods and exogenous climate drivers."

Main Results

• Major oceanic sources (extratropical Pacific, tropical Pacific, extratropical Atlantic, tropical Atlantic, Arctic) are the primary contributors to winter floods in coastal regions.
• Land remains a significant moisture source for hydrologic regions over the Midwest.
• Air masses from the Pacific lose substantial moisture when crossing western mountain ranges and subsequently gain moisture east of the Rockies, making land a key contributor to floods over the upper Midwest.
• Substantial variability in moisture source contributions is observed depending on flood severity in specific regions.
• Circulation patterns associated with extreme flood trajectories consistently reveal large-scale features, typically involving a deep low-pressure system delivering moisture.

Contributions

• Updates previous seminal studies on US flood hydroclimatology by leveraging more extensive and longer datasets.
• Provides a detailed, region-specific summary of moisture source contributions to winter floods across CONUS.
• Identifies specific atmospheric dynamics (moisture loss/gain over mountain ranges) explaining regional flood source contributions.
• Explores the influence of flood severity on moisture source contributions and characterizes associated large-scale circulation patterns.

Funding

Not specified in the provided abstract.

Citation

@article{Hwang2025LargeScale,
  author = {Hwang, Jeongwoo and Sankarasubramanian, A.},
  title = {Large‐Scale Moisture Sources and Delivery Pathways Contributing to Winter Floods in the US},
  journal = {Water Resources Research},
  year = {2025},
  doi = {10.1029/2025wr040353},
  url = {https://doi.org/10.1029/2025wr040353}
}