Tropical Highlights - July 2005

 

The pattern of global tropical sea surface temperature (SST) during July 2005 featured near-average SSTs everywhere, except positive anomalies in the tropical North Atlantic . The warmth in the tropical North Atlantic has been a persistent feature during the last several months. The SST anomaly in the Niño 3.4 region remained positive during July (latest value 0.5) while the Niño 1+2 anomaly was -0.6 (Fig. T18, Table T2). The oceanic thermocline, measured by the depth of the 20°C isotherm, featured near-average depth across the equatorial Pacific during July (Figs. T15, T16). Consistent with these conditions, oceanic temperatures at thermocline depth were near average throughout most of the equatorial Pacific (Fig. T17). The Tahiti - Darwin SOI has been near zero for the last two months (Table T1, Fig. T1). The overall patterns of convection, SST, low-level winds and upper-level winds were near average over central and eastern tropical Pacific during July, which is consistent with ENSO-neutral conditions. 

Excessive precipitation was observed over India and Southeast Asia , the western tropical Pacific (north of Papua New Guinea ), and the Gulf of Mexico (Fig. T26, Fig. E3). The former are consistent with enhanced convection associated with the development of the Asian summer monsoon system (Fig. T25), while the latter is consistent with the very active start to the Atlantic hurricane season.