[El Niño / La Niña] In October 2014, the NINO.3 SST was above normal with a deviation of +0.7°C (
Table and
Fig.1). SSTs were above normal in the western and eastern equatorial Pacific (
Fig.2 and
Fig.4). Subsurface temperatures were above normal in the western and central equatorial Pacific (
Fig.3 and
Fig.5). Atmospheric convective activities were near normal from near the date line to the eastern equatorial Pacific, and easterly winds in the lower troposphere were also near normal in the central equatorial Pacific (
Fig.5,
Fig.6 and
Fig.7). These oceanic and atmospheric conditions indicate that ENSO neutral conditions continued in the equatorial Pacific though the ocean state evolved toward El Niño conditions.
The subsurface warm waters in the equatorial Pacific in October (
Fig.3) tend to maintain warmer-than-normal SSTs in the eastern part. The JMA's El Niño prediction model predicts that the NINO.3 SST will be near normal or above normal during the northern hemisphere winter and spring (
Fig.9). In conclusion, although the continuation of ENSO neutral conditions may be possible, it is more likely that El Niño conditions will have developed in winter. We may have a possibility to make the diagnosis that El Niño conditions emerged in this summer, which depend on the oceanic conditions in the coming months.
[Western Pacific and Indian Ocean]
The area-averaged SST in the tropical western Pacific (NINO.WEST) region was near normal in October (
Fig.1). It is likely that the NINO.WEST SST will be near normal or below normal in the northern hemisphere winter and spring (
Fig.10).
The area-averaged SST in the tropical Indian Ocean (IOBW) region was near normal in October (
Fig.1). It is likely that the IOBW SST will be near normal in the northern hemisphere winter and spring (
Fig.11).