A possible cause of a higher correlation between PC1s and low latitude EAWM wind indices rather than the others of mid-high latitudes, is the modulation with other active climate features, such as ENSO. This plays a role in the maritime continent during the winter monsoon [36]. The ENSO is an important phenomena revealed by SST variability in the equatorial Pacific Ocean. Many studies indicate that there is an association between EAWM and ENSO [3,17–19]. In addition, there is a significant correlation of the northeasterly wind over the IDP represented by PC1s (hereafter, referred to as the northeast (NE) monsoon) with the low latitude EAWM characteristic. It is a possibility that there is another possible climate forcing influencing the variability of wintertime low-level wind over the IDP. This would be the forcing from SST variability in the Pacific Ocean and is interesting for revealing the relationship between NE monsoon and SST in the Pacific Ocean, which has not been completely investigated. The PC1s were employed to construct the correlation maps of these to sea surface temperature anomalies (SSTAs) for investigation, as shown in Figure 6.