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ENSO Quick
Look IRI ENSO Update / Forecast Technical ENSO Update Summary of Model Forecasts Monthly archive ENSO Update18 July 2006SummaryNeutral conditions exist in the tropical Pacific. As of mid-July sea surface temperatures are near 0.5C above average in the central equatorial Pacific, but don't significantly impact the ENSO SST index regions. SSTs appear to be warming in the far eastern equatorial Pacific, and are now above average. Based on the latest observations and forecasts, the probability of neutral conditions continuing through the July-August-September 2006 season is approximately 65%.General DiscussionSince April 2006 near-average temperatures have dominated the equatorial Pacific. The western and central equatorial Pacific have warmed to about 0.5 deg C above average since mid-May 2006, and the far eastern equatorial Pacific that had been colder than average earlier in the year has now warmed to above average. In addition, the equatorial heat content has become above average over the last several months, relative to the 1970-2001 climatology period. Coincident with the increasing heat content, anomalous low-level westerly winds in the western Pacific, although of small fetch, have generated some large-scale, though weak, sub-surface temperature anomalies. These sub-surface anomalies will likely need further reinforcement if they are to contribute to development of an El Niño event in the eastern Pacific.The observations and models suggest that neutral conditions will be in place through 2006. Out of a large set of dynamical and statistical forecast models, most predict neutral conditions continuing throughout 2006. Overall, based on model forecasts and current observations of the ocean surface and subsurface, the probability of a La Niña is much less than the climatologically expected odds of 25%. The probability of developing El Niño conditions is 35%, and that of maintaining neutral conditions through the end of 2006 is approximately 60%. Note 1 - Only models that produce a new ENSO forecast every month are included in the above statement.
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