March 14, 2017 (The Hindu)
THIRUVANANTHAPUAM, MARCH 14: Some global models seem to suggest that the tropical Pacific may relapse into an El Nino phase as early as July, when the South-West monsoon in India normally reaches its peak.
This comes after the previous monsoon proved indifferent to most parts of South India, which is now in the grip of a persistent drought.
According to the Australian Bureau of Meteorology (BoM), six of eight models it tracked suggested that El Nino thresholds may be reached by July.
But the Bureau sought to temper its outlook saying that forecast accuracy is low during this time of the year.
All eight models surveyed by the Bureau show steady warming of the central tropical Pacific Ocean over the next six months (covering the four-month-long Indian monsoon).
Giving an update, it said that currently, the Pacific is in a ‘neutral’ state (neither El Nino or La Nina). But model outlooks and recent warming in the Pacific mean there is an increased chance of El Nino.
The Bureau’s outlook is currently at El Nino ‘watch’, which means the likelihood of El Niño forming this year is around double the average chance at 50 per cent.
US model speak
Meanwhile, the US Climate Prediction Centre (CPC) is of the view that ‘neutral’ conditions in the Pacific may continue through at least spring 2017, with increasing chances of El Nino later.
Some dynamical model forecasts, including the NCEP CFSv2, anticipate an onset of El Ninolate in the spring (March-May 2017).
“Because of typically lower skill in forecasts made at this time of the year ... the forecaster consensus favors neutral phase during March-May with a 75 per cent chance,” the CPC said.
Thereafter, there are increasing odds for an El Nino toward the second half of this year (50- to 55 per cent chance from approximately July-December).
The International Research Institute for Climate and Society (IRI) at Columbia University said dynamical models favor El Nino during the early summer, while statistical models favour a ‘neutral’ phase into autumn.
(This article was published on March 14, 2017)