Threemonthmean SST and sea level anomalies forecast in the equatorial Pacific.


Time evolution of SST anomalies for the Nino3.4 (170W120W, 5S5N) regions up to 12 lead month.

Verification of monthly and seasonal SST anomaly forecast for the NINO3.4 (170W120W, 5S5N) region (lead month is defined as the time between the time of forecast and the beginning of predicted periods).


Verification of sea level anomalies at tide gauges (lead month is defined as the time between the time of forecast and the beginning of predicted periods).
Forecasts of the tropical Pacific SST and sea level anomalies
are presented here using a linear statistical model (Markov model). The
Markov model is constructed in a reduced multivariate EOF space of observed
sea surface temperature (SST) and sea level analysis using the methodology
of Xue and Leetmaa (2000). 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 model is trained for the 19811998 period, and is built with three multivariate EOFs
in which the anomalous fields of SST and sea level are equally weighted.
The model contains 12 monthly regression matrices (Xue et al. 2000).
Verification of crossvalidated monthly and seasonal SST anomalies for the NINO3.4 (170W120W, 5S5N) region (lead month is defined as the time between the time of forecast and the beginning of predicted periods).


The crossvalidated skill of SST in 198198.

The crossvalidated skill of sea level against sea level analysis and tide gauge observations.


Crossvalidated sea level anomaly hindcast at tide gauges.



Text file of the anomalous monthly SST for the Nino3.4 (170W120W, 5S5N) regions.

Text files of the anomalous seasonal SST for the Nino3.4 (170W120W, 5S5N) regions.

Text files of the monthly SST for the Nino3.4 (170W120W, 5S5N) regions.

Text files of the seasonal SST for the Nino3.4 (170W120W, 5S5N) regions.

The Markov model forecasts are published quarterly in Pacific ENSO Update . Further details on current conditions of El Nino and El Nino forecasts are found in Climate Diagnostics Bulletin from Climate Prediction Center .
References
Xue, Y. and A. Leetmaa, 2000: Forecasts of tropical Pacific SST and sea level using a Markov model. Geophys. Res. Lett. , 27, 27012704.
Xue, Y., A. Leetmaa, and M. Ji, 2000: ENSOprediction with Markov models: The impact of sea level. J. Climate, 13, 849871.
Xue, Y., M. A. Cane, S. E. Zebiak, and B. Blumenthal, 1994: On the prediction of ENSO: a study with a loworder Markov model. Tellus , 46A , 512528.
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