El Niño/La Niña Update (April 2005)

Sea-surface temperatures (SSTs) across a large area of the central equatorial Pacific
were up to 1°C warmer than normal through the latter part of 2004 and into early
2005. Expert interpretation of recent tendencies in SSTs and model projections,
however, suggest that the current situation is predominantly neutral. Although rapid
development over the next few months towards EI Nino or La Nina conditions is not
likely, this is the time of year when rapid developments can and do occur. Some
computer models are suggesting an elevated possibility of EI Nino development,
while a smaller set of models points to the possibility of La Nina development. Thus,
compared to the last update in August 2004, when warming was considered likely for
the remainder of 2004, evolution of the current situation is less certain. Careful
monitoring and frequent updating of conditions are therefore warranted.