Choi et al. (2026) Potential Sources of Predictability for the Surface Air Temperature over the CONUS during Boreal Winter

Identification

• Journal: Journal of Climate
• Year: 2026
• Date: 2026-07-14
• Authors: Nakbin Choi, Cristiana Stan, Bora Lee, Eunkyo Seo
• DOI: 10.1175/jcli-d-25-0495.1

Research Groups

• Department of Atmospheric, Oceanic and Earth Sciences, George Mason University
• Center for Ocean–Land–Atmosphere Studies, George Mason University
• Department of Environmental Atmospheric Sciences, Pukyong National University

Short Summary

This study examines the dominant patterns of surface air temperature bias in winter over the contiguous United States (CONUS) using deterministic reforecasts from the NOAA Unified Forecast System prototype 8 (UFS P8). The analysis reveals two leading modes of winter SAT bias associated with Arctic variability, tropical forcing, and land–atmosphere interactions.

Objective

• Investigate the sources of predictability for surface air temperature over the CONUS during boreal winter

Study Configuration

• Spatial Scale: Continental United States (CONUS)
• Temporal Scale: December-March 2011-18

Methodology and Data

• Models used: NOAA Unified Forecast System prototype 8 (UFS P8)
• Data sources: Deterministic reforecasts from UFS P8 for the period of December-March 2011-18

Main Results

• Two leading modes of winter SAT bias were identified using empirical orthogonal function analysis:
  • Mode 1 is linked to Arctic surface temperature variability over the East Siberian-Chukchi Seas, where forecast skill decays beyond week 2.
  • Mode 2 features a dipole pattern associated with an exaggerated upper-level circulation response and local surface processes.

Contributions

• This study highlights land surface processes as a barrier to advancing extended-range forecast skill for S2S forecasts of winter SAT over the CONUS.
• The findings suggest that surface warming is primarily driven by cloud-induced downward longwave radiation, but its magnitude and variability are modulated by land-atmosphere interactions via surface energy partitioning.

Funding

• This research was funded by the National Oceanic and Atmospheric Administration (NOAA) under grant number [insert grant number].

Citation

@article{Choi2026Potential,
  author = {Choi, Nakbin and Stan, Cristiana and Lee, Bora and Seo, Eunkyo},
  title = {Potential Sources of Predictability for the Surface Air Temperature over the CONUS during Boreal Winter},
  journal = {Journal of Climate},
  year = {2026},
  doi = {10.1175/jcli-d-25-0495.1},
  url = {https://doi.org/10.1175/jcli-d-25-0495.1}
}