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

CPC Search
HOME > Expert Assessments > Climate Diagnostics Bulletin > Tropical Highlights

Tropical Highlights - February 2003

Pacific warm episode (El Niņo) conditions continued to weaken during February 2003 as sea surface temperature (SST) anomalies decreased across the equatorial Pacific (Table T2). SSTs remained more than 1.0°C above normal in the central Pacific between 170°E and 155°W, but were slightly cooler than normal east of 120°W (Fig. T18). The anomalies in all four Niņo region indices decreased for the second consecutive month, with the largest decrease again occurring in the Niņo 3 region (Table T2, Fig. T5). The values observed in both Niņo 3 and Niņo 3.4 were the smallest since May 2002 (Table T2, Fig. T5).

Consistent with weakening El Niņo conditions, the oceanic thermocline continued to shoal across the east-central and eastern equatorial Pacific, with near-normal depths observed during February across the central and eastern Pacific (Figs. T15, T16). The shoaling has contributed to a decrease in upper-ocean heat content, with anomalies decreasing to 1-2°C above normal in the central and east-central Pacific (Fig. T17). Also associated with this decrease in thermoclime depth, negative ocean temperature anomalies (1-2°C below normal) were recorded beneath the positive anomalies in the east-central Pacific.

Convection (precipitation and cloudiness) remained enhanced across the central equatorial Pacific and was near-normal or slightly above normal over Indonesia during February (Fig. T25). Enhanced convection has persisted over the central equatorial Pacific since August (Fig. T11), consistent with ongoing warm episode conditions. Elsewhere, the pattern of convection in the south-central Pacific reflected an eastward shift from normal in the position of the South Pacific Convergence Zone.

The tropical sea-level pressure (SLP) pattern during February featured small negative SLP anomalies over the Indian and Pacific oceans and small positive anomalies over the Atlantic (Fig. T19). This pattern was associated with negative values of both the Tahiti-Darwin Southern Oscillation Index (SOI) (-1,2) and the equatorial SOI (-0.2) (Figs. T1, T2, respectively). The SOI has been negative for the past twelve months (Fig. T1).

NOAA/ National Weather Service
National Centers for Environmental Prediction
Climate Prediction Center
5200 Auth Road
Camp Springs, Maryland 20746
Climate Prediction Center Web Team
Page last modified: January 15, 2002
Disclaimer Privacy Notice