El Nino Update
By Paul Homewood
Most of the indicators are now pointing to ENSO-neutral conditions by late spring/early summer.
The latest ENSO update from the NWS shows the warm water in the central and eastern Pacific continuing to break up and dissipate.
The change in the last four weeks is evident:
More significantly, there has been a dramatic reduction in upper ocean temperatures since the middle of January, with them virtually back to average.
Negative anomalies largely remain below the surface, but are spreading eastwards. Once the remaining hot spot has evaporated away in the east, there will be an awful lot of cold water around.
All of this warmth at the sea surface has had to go somewhere, and that somewhere is the atmosphere. The UAH anomaly has jumped from 0.54C to 0.83C. However, this sort of increase is not uncommon during El Ninos – there was a jump of 0.27C in 1998 between March & April, and 0.38C from December 2009 to January 2010.
Indeed what stands out is that we get such large monthly variations, due to natural oceanic changes, which dwarf claimed global warming trends.
Generally atmospheric temperatures peak about six months after the El Nino, which according to the MEI was last August. I would therefore be surprised if we have not seen the peak in temperatures, or at least something very close.
However, if La Nina conditions return later in the year, we will be unlikely to see much effect on temperatures till next year.