Spanish Version (Español -- Courtesy of INFOCLIMA, Peru)

Synopsis: ENSO-neutral conditions are expected to continue for the next one to three months, with a 50% chance that weak El Niño conditions will develop by the end of 2006.

Equatorial surface and subsurface temperature anomalies increased during July 2006, with SST anomalies greater than +0.5C observed in most of the equatorial Pacific between 130ºE and 140ºW (Fig. 1). As a result, positive SST anomalies were observed in all of the Niño regions (Fig. 2). During July, low-level (850-hPa) easterly winds were weaker than average across most of the equatorial Pacific, and the Southern Oscillation Index (SOI) was negative for the third consecutive month. Beginning in February the basin-wide upper ocean heat content increased, and since early April positive anomalies have been observed (Fig. 3). Positive upper-ocean heat content anomalies are usually a precursor to warm (El Niño) episodes.

The statistical and coupled model forecasts range from ENSO-neutral to weak warm (El Niño) episode conditions for the remainder of 2006 and into early 2007 (Fig. 4). The forecasts are consistent with the recent build up in upper-ocean heat content along the equator (Fig. 3), indicating a trend toward warm-episode conditions. In the absence of any strong intraseasonal (Madden-Julian Oscillation – MJO) activity, a continued slow trend toward warm-episode conditions is expected. Therefore, ENSO-neutral conditions are expected to continue for the next one to three months, with a 50% chance that weak El Niño conditions will develop by the end of 2006.

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 7 September 2006. To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message: ncep.list.enso-update@noaa.gov.