Tropical Highlights - November 2006

 

The pattern of tropical sea surface temperature (SST) anomalies during November 2006 featured warmer-than-average temperatures across the central and eastern Pacific (Fig. T18).  Accordingly, the SST anomalies in the Niño 4, Niño 3.4  and Niño 1+2  regions remained positive (latest values of 1.3, 1.2 and 1.0, respectively)(Table T2). Meanwhile, the Tahiti – Darwin SOI is near zero (latest value: 0.1) for the first time since February 2006 (Table T1, Figs. T1).

The oceanic thermocline, measured by the depth of the 20ºC isotherm along the equator, featured above average depth across the central and eastern Pacific during November (Figs. T15, T16).  Consistent with these conditions, oceanic temperatures at thermocline depth were 2-3ºC above average throughout most of the equatorial Pacific (Fig. T17).

During November 2006, low-level westerly (easterly) anomalies (more than 3.0 m s-¹) were observed over the eastern equatorial Pacific (eastern Indian Ocean ) (Fig. T20).  Suppressed convection (below-average rainfall amounts) was observed across the eastern Indian Ocean and Indonesia , while enhanced convection (above-average rainfall amounts) was seen over the western Indian Ocean as well as the equatorial Pacific, west of the Date Line (Figs. T25 and E3).