Skip Navigation Links 
NOAA logo - Click to go to the NOAA home page National Weather Service   NWS logo - Click to go to the NWS home page
Climate Prediction Center

HOME > Expert Assessments > Climate Diagnostics Bulletin
Forecast Forum - March 2002

The canonical correlation analysis (CCA) forecast of SST in the central Pacific (Barnett et al. 1988, Science, 241, 192-196; Barnston and Ropelewski 1992, J. Climate, 5, 1316-1345), is shown in Figs. F1 and F2. This forecast is produced routinely by the Prediction Branch of the Climate Prediction Center. The predictions from the National Centers for Environmental Prediction (NCEP) coupled ocean/atmosphere model (Ji et al. 1998, Mon. Wea. Rev, 126, 1022-1034) are presented in Figs. F3 and F4a, F4b. Predictions from the latest version of the LDEO model (Chen, D., M. A. Cane, S. E. Zebiak, Rafael Canizares and A. Kaplan, 2000, Geophys. Res. Let., accepted) are shown in Figs. F5 and F6. Predictions using linear inverse modeling (Penland and Magorian 1993, J. Climate, 6, 1067-1076) are shown in Figs. F7 and F8. Predictions from the Scripps / Max Planck Institute (MPI) hybrid coupled model (Barnett et al. 1993, J. Climate, 6, 1545-1566) are shown in Fig. F9.   Predictions from the ENSO-CLIPER statistical model (Knaff, J. A. and C. W. Landsea 1997, Wea. Forecasting, 12, 633-652) are shown in Fig. F10.

The CPC and the contributors to the Forecast Forum caution potential users of this predictive information that they can expect only modest skill.


Based on the recent evolution of the observed oceanic surface and subsurface temperature patterns, the SST predictions, and the time of year, it seems likely that warm-episode (El Niņo) conditions will continue to develop in the tropical Pacific during the next 3 months and persist during the remainder of 2002.


The evolution towards a warm (El Niņo) episode continued in the equatorial Pacific during March 2002, with warmer-than-normal sea surface temperatures (Fig. T9) and subsurface temperatures (Fig. T15) observed throughout the equatorial Pacific. An area of equatorial sea surface temperature anomalies exceeding +1° C continued to expand westward from the South American coast during the month (Figs. T9, T18). Ocean surface temperatures remained as much as 2-3° C (up to 6°F) above average near the coasts of Ecuador and northern Peru during March. This warming has been accompanied by an increase in rainfall over the extreme eastern tropical Pacific, including the Galapagos Islands (Figs. T25, E3). As a result, parts of South America (Ecuador and northern Peru) are already experiencing El Niņo-related impacts. Persistent rain and cloudiness have also been observed over the tropical west-central Pacific, from Papua New Guinea eastward to the date line (180° W) (Figs. T25, E3).

It is important to emphasize that these conditions represent the early stages of El Niņo and that mature El Niņo conditions will take at least several more months to develop. Several of the atmospheric indices, including both lower-tropospheric and upper-tropospheric wind indices, do not reflect El Niņo/ Southern Oscillation (ENSO) conditions at this time (Table T1). However, these indices are often inconsistent in the early stages of El Niņo.

The warming of surface and subsurface waters in the eastern equatorial Pacific was due to the arrival of an oceanic Kelvin wave that propagated eastward from the central equatorial Pacific starting in mid-December. This Kelvin wave was triggered by tropical intraseasonal (30-60 day) fluctuations associated with the Madden Julian Oscillation (MJO). Whereas MJO activity was evident throughout the global tropics during much of the NH winter, no MJO activity was observed during March 2002 . However, the period from now thru May is a critical time, when MJO activity can generate equatorial westerly wind bursts capable of producing Kelvin wave activity. Without such activity a continued slow evolution towards mature El Niņo conditions would be expected to occur through the spring and summer of 2002.

The latest statistical and coupled model predictions (Figs. F1, F2F3F4a,   F4bF5F6F7F8,   F9) show a spread from near-normal conditions to moderate warm-episode conditions during the remainder of 2002. The coupled models and some statistical techniques that incorporate subsurface oceanic conditions indicate a slow evolution to weak or moderate warm-episode (El Niņo) conditions during the next several months. Other techniques indicate that conditions will remain near normal for the remainder of 2002. Based on the recent evolution of the observed oceanic conditions and the SST predictions, it appears most likely that further development toward mature El Niņo conditions will occur over the next 3-9 months.

Weekly updates of SST, 850-hPa wind, OLR, and the equatorial subsurface temperature structure are available on the Climate Prediction Center homepage at: (Weekly Update).

NOAA/ National Weather Service
NOAA Center for Weather and Climate Prediction
Climate Prediction Center
5830 University Research Court
College Park, Maryland 20740
Page Author: Climate Prediction Center Internet Team
Page last modified: August 24, 2007
Information Quality
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities