Figure shows that monthly mean SST retrieved from the TMI and its deviation from the climatological monthly mean compiled by the Japan Meteorological Agency. Yellow and red areas indicate higher SST than normal years. In Figure, higher SST regions in the tropics correspond well to heavy rainfall regions in Figure 1.

Since the El Nino warm episode continued in February 1998, there are higher than normal SSTs in the Eastern equatorial Pacific and lower than normal SSTs in the western tropical Pacific. Related to those positive and negative SST anomalies, the heavy rainfall region extending over the equatorial Pacific normal years and less rainfall was observed in the western tropical Pacific. Such a shift of the maximum rainfall region in the tropics linked to convective activity variations should significantly affect world weather.