The SST is the NCEP SST analysis (Reynolds and Smith 1994); the sea level is from the NCEP ocean analysis (Behringer et al. 1998). All the data are monthly values averaged in grid boxes of 6 degrees in longitude and 2 degrees in latitude, and cover the tropical Pacific region within 19 degrees of the equator.

The Markov model is built with three multivariate EOFs in which the anomalous fields of SST and sea level are equally weighted. The model contains 12 monthly transition matrices (Xue et al. 2000).

Figure 1 suggests that the current coldSST anomalies in the central equatorial Pacific will probably sustain until the end of the year at about -0.5 to -1.0 degree. Since the forecast skill tends to degrade a lot when spring season is past, we expect that the recent forecast initiated from April 2000 is more reliable than that initated from December 1999, which suggests that the Pacific SST will return to norm by summer.

Figure 2 suggests that the current positive sea level anomalies in the western Pacific and negative sea level anomalies in the eastern Pacific will likely sustain until the end of the year. We expect that the recent forecast initiated from April 2000 is more reliable than that initated from December 1999, which suggests that the positive sea level anomalies in the north-western Pacific and negative sea level anomalies in the eastern Pacific will diminish quickly in spring, and positive sea level anomalies in the western equatorial Pacific will propagate to the central equatorial Pacific by summer.

For the full suite of model results, including skill analyses, please go to Yan Xue's Markov model home page.