BEIJING, Oct. 9(Xinhuanet) -- WMO has released new El Nino/La Nina update which introduced the current situation and outlook of El Nino/La Nina.
According to the update, neutral conditions (neither El Nino nor La Nina) continue in the tropical Pacific. Model forecasts and expert opinion suggest that neutral conditions are likely to be maintained through the boreal autumn of 2013 and winter 2013-14. Two or more consecutive years of neutral conditions have been observed in the past and the situation is not unusual. National Meteorological and Hydrological Services and other agencies will continue to monitor the conditions over the Pacific and provide outlooks to assess the most likely state of the climate through the remainder of 2013 and into early 2014.
Since the boreal spring of 2012, El Nino-Southern Oscillation (ENSO) indicators in the tropical Pacific (e.g., tropical Pacific sea surface temperatures, sea level pressure, cloudiness and trade winds) have generally been at neutral levels, indicating that neither El Nino nor La Nina conditions have been present. Since May 2013, sea surface temperatures have been well below average in the far eastern tropical Pacific, only recently returning toward normal. However, these cold sea surface temperatures have been positioned too far to the east to be considered indicative of a basin-wide La Nina episode, even though they caused some minor impacts over local climate conditions in western parts of South America.
The latest outlooks from international climate models and expert opinion suggest that sea surface temperatures and atmospheric anomalies associated with El Nino or La Nina are most likely to remain neutral through the end of 2013 and into early 2014. Less than one-fifth of the models surveyed predict weak La Nina conditions to develop during the October to December period, and likewise less than one-fifth predict weak El Nino development during that period and into the first quarter of 2014. Therefore, while there is a very slight chance for La Nina or El Nino development during the next one or two seasons, neutral ENSO conditions are considered by far the most likely scenario.
It is important to note that El Nino and La Nina are not the only factors that drive global climate patterns. At the regional level, seasonal outlooks need to assess the relative impacts of both the El Nino/La Nina state and other locally relevant climate drivers. For example, the negative Indian Ocean Dipole conditions, established in May, dissipated during August and neutral conditions are currently prevailing. Locally applicable information is available via regional/national seasonal climate outlooks, such as those produced by WMO Regional Climate Centres (RCCs), Regional Climate Outlook Forums (RCOFs) and National Meteorological and Hydrological Services (NMHSs).
In summary, over the last 12 months, conditions have mainly remained neutral (neither El Nino nor La Nina). As of mid-September 2013, outlooks indicate that these neutral conditions are most likely to continue into early 2014.