Xiang et al. (2026) Dual physical pathways shape subseasonal-to-seasonal predictability of North American summer heat extremes

Identification

• Journal: Communications Earth & Environment
• Year: 2026
• Date: 2026-09-02
• Authors: Baoqiang Xiang, Lucas Harris, Gan Zhang, Xiuyuan Ding
• DOI: 10.1038/s43247-026-03991-1

Research Groups

• NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA
• Cooperative Programs for the Advancement of Earth System Science, University Corporation for Atmospheric Research, Boulder, CO, USA
• Department of Climate, Meteorology & Atmospheric Sciences, University of Illinois Urbana-Champaign, Urbana, IL, USA
• Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ, USA

Short Summary

This study identifies two dominant sources of subseasonal-to-seasonal predictability for weekly hot days across North America: an ocean-forced mode associated with a Pacific Decadal Oscillation-like sea surface temperature pattern and an internally generated atmospheric mode linked to the summer Arctic Oscillation and summer North Atlantic Oscillation. The findings provide a scientific basis for improving extended-range early warnings of heat extremes.

Objective

• Investigate the physical mechanisms governing subseasonal-to-seasonal predictability of North American heat extreme events

Study Configuration

• Spatial Scale: Continental-scale analysis over North America
• Temporal Scale: Subseasonal to seasonal (2 weeks to 1 season)

Methodology and Data

• Models used: GFDL SPEAR S2S prediction system
• Data sources: Satellite, observation, reanalysis

Main Results

• Two dominant modes of predictability: ocean-forced mode associated with a Pacific Decadal Oscillation-like sea surface temperature pattern (MPM1) and internally generated atmospheric mode linked to the summer Arctic Oscillation and summer North Atlantic Oscillation (MPM2)
• MPM1 exhibits high skill at week 2, while MPM2 shows strong subseasonal variability
• Land-atmosphere coupling plays a critical role in amplifying heat extremes

Contributions

• This study provides new insights into the physical mechanisms governing subseasonal-to-seasonal predictability of North American heat extreme events
• The findings have significant implications for improving extended-range early warnings of heat extremes

Funding

• Not specified

Citation

@article{Xiang2026Dual,
  author = {Xiang, Baoqiang and Harris, Lucas and Zhang, Gan and Ding, Xiuyuan},
  title = {Dual physical pathways shape subseasonal-to-seasonal predictability of North American summer heat extremes},
  journal = {Communications Earth & Environment},
  year = {2026},
  doi = {10.1038/s43247-026-03991-1},
  url = {https://doi.org/10.1038/s43247-026-03991-1}
}