El Niño conditions are likely
to continue into early 2007.
Equatorial Pacific SST anomalies greater than +0.5ºC
were observed in most of the equatorial Pacific, with anomalies exceeding +1.0ºC
between 165ºE and 165ºW and in several areas east of 150ºW (Fig.
1). The latest SST departures in the Niño regions are all greater than +0.5
Beginning in February the
basin-wide upper ocean heat content increased, and since early April positive
anomalies have been observed (Fig. 3). Since early July
weaker-than-average low-level equatorial easterly winds have been observed
across most of the equatorial Pacific. In September the
Southern Oscillation Index (SOI) was negative for the fifth consecutive month. Collectively,
these oceanic and atmospheric anomalies are consistent with
the early stages of El Niño in the tropical Pacific.
Over the past several months most of the statistical
and coupled model forecasts have trended towards warmer conditions in the
tropical Pacific through the Northern Hemisphere winter. The latest NCEP coupled
forecast system (CFS) predictions indicate El Niño conditions for the remainder of
2006 and into the NH spring (SH fall) 2007 (Fig. 4). More than two-thirds of
the other statistical and coupled model predictions also indicate El Niño
conditions during the same period (Fig. 5).
Typical El Niño effects are
likely to develop over North America during the upcoming winter season,
including warmer-than-average temperatures over western and central Canada, and over the western and northern
United States, wetter-than-average conditions over portions of the U.S. Gulf Coast and Florida, and drier-than-average
conditions in the Ohio Valley and the Pacific Northwest. Global effects that can be expected during November-March include
drier-than-average conditions over most of Malaysia, Indonesia, some of the U.S.-affiliated islands in the tropical
North Pacific, northern South America and southeastern Africa,
and wetter-than-average conditions over equatorial East Africa, central South America (Uruguay, northeastern
Argentina, and southern Brazil) and along the coasts of Ecuador and northern Peru.
This discussion is a consolidated effort of NOAA and its funded institutions.
Oceanic and atmospheric conditions
are updated weekly on the Climate
Prediction Center website
(El Niño/La Niña
Current Conditions and Expert Discussions). Forecasts for the evolution of El Niño/La Niña are updated monthly in the
Forecast Forum section of CPC's Climate
Diagnostics Bulletin. The next ENSO Diagnostics Discussion is scheduled for
November 2006. To receive
an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail