Tropical Highlights - May 2006
pattern of tropical sea surface temperature (SST) anomalies in the Pacific
during May 2006 featured slightly
warmer than average temperature west of the date line and near-average
conditions east of the date line, except for an area
of negative anomalies near the South American coast (Fig. T18).
Accordingly, the SST anomaly in the Nino 4 region is slightly
positive (0.2), while the anomalies are near zero in the Nino 3 and Nino 3.4
regions, and -0.4 in the Nino 1+2 region (Table
– Darwin SOI became
negative (-0.8) in response to higher than average pressure over Darwin (Table T1, Figs. T1, T19).
oceanic thermocline, measured by the depth of the 20ºC isotherm along the
equator, featured slightly deeper-than-average depth across the central and
east-central Pacific and near-average depth in the eastern Pacific during
May (Figs. T15,
with these conditions, equatorial oceanic temperatures at thermocline depth
were 1-2ºC above average in the central and east-central equatorial
Pacific, while temperatures were slightly below average (0ºC to -1ºC) in
the far eastern Pacific (Fig. T17).
low-level winds were near-average throughout the equatorial Pacific, and
anomalous cross-equatorial, monsoonal flow was observed in the western
Convection returned to near-average along the equator over the
Maritime Continent, with regions of enhanced precipitation just north and
south of the equator. Diminished
precipitation was observed over most of the central and eastern equatorial
Pacific and equatorial
T25, T26, E3).