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The El Niño/Southern Oscillation (ENSO) is the major driver of interannual variations of the western North Pacific (WNP) tropical cyclones (TCs). Realistic reproduction of ENSO-WNPTC teleconnection in coupled models (CGCMs) is thus crucial for improved seasonal-to-interannual prediction of WNPTC activity. Here, basing on the outputs of six pairs of high-resolution (HR) and low-resolution (LR) CGCMs participating the HighResMIP-PRIMAVERA project, we showed that the HR models outperform the LR ones in reproducing the observed increase of TC genesis in the southeastern WNP but the decrease in the northwestern WNP in the developing years of El Niño. The better performance of HR than LR models is on one hand due to the generally increased frequency and variability of TCs in the HR models. On the other hand, the teleconnection of El Niño to the WNP shows a dipole circulation difference between the HR and LR models with an anomalous cyclone in the southeastern WNP and anticyclone in the northwestern WNP, which enhances the dipole TC genesis anomalies in the HR compared to the LR models. The teleconnection difference stems from the westward shift of the ENSO-related SST and convection anomalies in the tropical Pacific in the HR compared to the LR models, which may be ultimately linked to the reduced cold tongue biases in the HR models.

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The El Niño/Southern Oscillation (ENSO) is the major driver of interannual variations in the western North Pacific (WNP) tropical cyclones (TCs). Realistic reproduction of ENSO-WNPTC teleconnection in coupled models (CGCMs) is thus crucial for improved seasonal-to-interannual prediction of WNPTC activity. Here, basing on the outputs of six pairs of high-resolution (HR) and low-resolution (LR) CGCMs participating the HighResMIP-PRIMAVERA project, we showed that both HR and LR models can reproduce well the increased/decreased TC genesis and track in the southeastern WNP but the decreased/increased in the northwestern WNP in the developing years of El Niño/La Niña, but the HR models outperform the LR by simulating higher anomalous amplitudes closer to the observed. The better performance of HR than LR models is on one hand due to the generally increased frequency and variability of TCs in the HR models. On the other hand, the teleconnection of El Niño/La Niña to the WNP shows a dipole circulation difference between the HR and LR models with an anomalous cyclone/anticyclone in the southeastern WNP and anticyclone/cyclone in the northwestern WNP, which enhances the dipole TC genesis and track anomalies in the HR compared to the LR models. The teleconnection difference stems from the location differences in the ENSO-related SST and convection anomalies in the tropical Pacific, which may be ultimately linked to the reduced cold tongue biases in the HR compared to the LR models.

The extreme precipitation (EP) in the early- and late-rainy seasons in Southern China is investigated from the perspective of moist static energy (MSE). At the synoptic timescale, the EP is accompanied by the charge-discharge paradigm of the vertically integrated MSE (<MSE>); the positive <MSE> anomaly reaches the peak one day before EP and decreases quickly during the event. The charge-discharge paradigm of <MSE> is dominated by the horizontal and vertical advection, respectively. However, synoptic systems responsible for the <MSE> charge in the early- and late-rainy seasons are different due to the different horizontal distributions of climatological MSE in the lower troposphere caused by the northward migration of solar radiation and monsoon system. At the interannual timescale, more EP in the early-/late-rainy season is associated with the higher seasonal-mean <MSE> that can be caused by the anomalous anticyclone/cyclone in the western North Pacific induced by the SST anomalies in the tropical Indian Ocean and central North Pacific/the tropical Pacific. The multi-model ensemble mean of CMIP6 models reproduces well the observed <MSE>-EP relationship in both the historical and SSP5-8.5 runs. Moreover, the mean state of <MSE> increases in the SSP5-8.5 compared to historical runs along with more frequent occurrence of EP events. Hence, <MSE> can serve as a useful metric for studying EP in Southern China at various timescales.