Tropical cyclone occurrences were above the long-term averages during the 1996-97 season. The weak La Niña phase which characterised 1996 declined and some early El Niño indicators emerged by the end of the season. These included the appearance of strong westerly equatorial wind anomalies near the date-line, increasing sea-surface temperature in the near-equatorial central and eastern Pacific, a fall of the Southern Oscillation Index to negative values and increased convective activity in the South Pacific convergence zone. The monsoon in the summer hemisphere was of average development or better, with strongest anomalies in the southwest Pacific. Three major cycles of the 30 to 60-day intraseasonal oscillation were diagnosed. The 26 cyclones that formed spanned every month (July 96-June 97) except August and September.
Hanstrum et al. (Wed,) studied this question.