This study aims to understand the role of near-surface temperatures in predicting US climatic extremes using the North American Multi-Model Ensemble (NMME) system. Here, the forecasting skill was measured by anomaly correlation coefficient (ACC) between the observed and forecasted precipitation (PREC)/2-meter air temperature (T2m) anomalies over the contiguous United States (CONUS) during 1982–2012. The strength of the T2m–PREC coupling was measured by ACC between observed PREC and T2m or forecasted PREC and T2m over the CONUS. We 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 T2m–PREC coupling was weaker or stronger than the 1982–2012 climatology (ACC: −0.34). We found that most of the NMME models show the bias of stronger T2m–PREC coupling than the observed coupling over 1982–2012, indicating that they failed to reproduce the interannual variability of T2m–PREC 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 T2m–PREC coupling despite the fact that the forecasting skill is year-dependent and model-dependent. Most of the NMME models show the limited seasonal forecasting skill of the PREC surplus from active Atlantic tropical cyclones in the summer of 2004 and thus fail to reproduce weak T2m–PREC coupling. Lastly, we explored how the role of sea surface temperatures in predicting T2m and PREC. The findings of this study suggest a need for the selective use of the current NMME seasonal forecasts for US droughts and pluvials.

这项研究旨在了解近地表温度在使用北美多模式合奏（NMME）系统预测美国极端气候中的作用。在这里，预报技能是根据1982-2012年间连续美国（CONUS）上观测到的和预测的降水（PREC）/ 2米气温（T2m）异常之间的异常相关系数（ACC）来衡量的。T2m–PREC耦合的强度是通过ACC在CONUS上观测到的PREC和T2m或预测的PREC和T2m之间进行测量的。我们还评估了2004年夏季（PREC和T2m之间的空间异常相关性：0.05），2011年（-0.65）和2012年（-0.60）时T2m-PREC耦合弱于或强于1982年的NMME预测技能。 2012年气候学（ACC：−0.34）。我们发现，大多数NMME模型都表现出比1982-2012年间观测到的耦合更强的T2m-PREC耦合的偏差，这表明它们未能重现T2m-PREC耦合的年际变化。尽管预报技能是依赖于年份和依赖模型的，但一些能够熟练预测T2m的NMME模型通过强大的T2m-PREC耦合显示了对2011年和2012年降水异常和美国干旱的熟练预测。大多数NMME模型都显示出2004年夏季大西洋大西洋热带气旋活跃时PREC盈余的季节性预报能力有限，因此无法再现弱的T2m-PREC耦合。最后，我们探讨了海面温度在预测T2m和PREC中的作用。