Sripathi et al. (2026) Early but Anomalous Onset of the 2025 Indian Summer Monsoon

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

Identification

• Journal: Journal of Climate
• Year: 2026
• Date: 2026-07-23
• Authors: G. Sripathi, Krishna Kishore Osuri, Dandi Appala Ramu, A. Suryachandra Rao
• DOI: 10.1175/jcli-d-25-0596.1

Research Groups

• Indian Institute of Tropical Meteorology (IITM)
• National Centre for Medium Range Weather Forecasting (NCMRWF)

Short Summary

This study investigates the synoptic- and large-scale air–sea processes that triggered the 2025 early onset of the Indian summer monsoon, highlighting key atmospheric and oceanic factors contributing to this event.

Objective

• Investigate the multiscale mechanisms for monsoon onset and improve subseasonal prediction and numerical model performance

Study Configuration

• Spatial Scale: Regional (Indian subcontinent)
• Temporal Scale: Intraseasonal (days to weeks)

Methodology and Data

• Models used: Not specified in the paper, but likely used numerical weather prediction models for analysis
• Data sources: Satellite data, observation, reanalysis

Main Results

• Enhanced land–sea thermal contrast (>4°C) and strong meridional tropospheric temperature gradient (∼6°C) created a favorable thermodynamic background
• Upper-tropospheric heating extended equatorward to ∼15°N, unlike its climatological confinement over 25°–30°N during other early and normal-onset years
• Stronger low-level jet (∼14 m s −1 ) enhanced moisture transport from the Arabian Sea and Bay of Bengal branches
• Madden–Julian oscillation transitioned from phase 7 (10 days before onset) to phase 4 (at onset), further supporting the monsoon advancement

Contributions

• This study improves our understanding of multiscale mechanisms for monsoon onset, highlighting the synergistic interaction of thermodynamic forcing and upper-level dynamics
• The findings can help improve subseasonal prediction and numerical model performance for monsoon forecasts

Funding

• Not specified in the paper

Citation

@article{Sripathi2026Early,
  author = {Sripathi, G. and Osuri, Krishna Kishore and Ramu, Dandi Appala and Rao, A. Suryachandra},
  title = {Early but Anomalous Onset of the 2025 Indian Summer Monsoon},
  journal = {Journal of Climate},
  year = {2026},
  doi = {10.1175/jcli-d-25-0596.1},
  url = {https://doi.org/10.1175/jcli-d-25-0596.1}
}