EGU21-1957
https://doi.org/10.5194/egusphere-egu21-1957
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

NMME-based Assessment of Prediction Skills of US Summertime Droughts and Pluvials: Role of Near-surface Temperature Prediction Skill

Jonghun Kam1, Sungyoon Kim2, and Joshua Roundy3
Jonghun Kam et al.
  • 1Division of Environmental Science and Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea (jhkam@postech.ac.kr)
  • 2Department of Construction, Civil and Environmental Engineering, The University of Alabama, Tuscaloosa, AL USA
  • 3Department of Civil, Environmental, and Architectural Engineering, The University of Kansas Lawrence, KS USA

This study used the North American Multi-Model Ensemble (NMME) system to understand the role of near surface temperature in the prediction skill for US climate extremes. In this study, the forecasting skill was measured by anomaly correlation coefficient (ACC) between the observed and forecasted precipitation (PREC) or 2-meter air temperature (T2m) over the contiguous United States (CONUS) during 1982–2012. The strength of the PREC-T2m coupling was measured by ACC between observed PREC and T2m or forecasted PREC and T2m over the CONUS. This study also assessed the NMME forecasting skill for the summers of 2004 (spatial anomaly correlation between PREC and T2m: 0.05), 2011 (-0.65), and 2012 (-0.60) when the PREC-T2m coupling is weaker or stronger than the 1982–2012 climatology (ACC:-0.34). This study found that most of the NMME models show stronger (negative) PREC-T2m coupling than the observed coupling, indicating that they fail to reproduce interannual variability of the observed PREC-T2m coupling. Some NMME models with skillful prediction for T2m show the skillful prediction of the precipitation anomalies and US droughts in 2011 and 2012 via strong PREC-T2m coupling despite the fact that the forecasting skill is year-dependent and model-dependent. Lastly, we explored how the forecasting skill for SSTs over north Pacific and Atlantic Oceans affects the forecasting skill for T2m and PREC over the US. The findings of this study suggest a need for the selective use of the current NMME seasonal forecasts for US droughts and pluvials.

How to cite: Kam, J., Kim, S., and Roundy, J.: NMME-based Assessment of Prediction Skills of US Summertime Droughts and Pluvials: Role of Near-surface Temperature Prediction Skill, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1957, https://doi.org/10.5194/egusphere-egu21-1957, 2021.

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