El Nino Update
By Paul Homewood
At the risk of sticking my neck out! But there are signs that the current El Nino may just be starting to run out of steam.
The MEI Index peaked in August/September last year. but had a small uptick again last month. However, the latest NOAA ENSO Advisory suggests this was a temporary blip.
The weekly anomalies below show the warm pool steadily shrinking from the east.
Compared to a month ago, there has been a rapid cooling off across much of most of the region.
Upper ocean temperatures in the Central and Eastern Pacific have also fallen back after the January blip.
Atmospheric temperatures tend to lag ENSO changes by about three to six months. Comparing the evolution of the current El NIno with that of 1997/8, we see that it started earlier in the year. Indeed there were weak El Nino conditions through most of 2014, which were reflected in last year’s temperatures.
However, so far at least, the 1997/8 event peaked higher. There is still a chance that the index could increase this spring, as it did in 1998.
Unless it does, though, it is likely that atmospheric temperatures either peaked last month, or will this month.
It is too early to predict where temperature anomalies will end up for 2016, but it is now beginning to look extremely unlikely that they will top 1998.