In the last three months, positive temperature anomaly across the tropical Pacific have been associated with the mature phase of El Niño to achieve its peak (Figure 1). This presented ideal conditions for tropical cyclone genesis and was associated with the development of Tropical Cyclone Tuni. Tropical Cyclone Tuni is the first named tropical cyclone of the 2015/2016 season. El Niño is expected to be in its mature phase during the first half of 2016. Then, the positive sea surface temperature SST anomalies in the central and eastern equatorial Pacific are expected to start weakening.
The forecasts for December-January-February (DJF) 2015 show the positive (warmer) temperature anomalies to prevail over the globe. Strongly enhanced probability for above normal temperature is predicted for eastern and central Pacific as well as western and eastern Pacific. Below normal temperatures are highly probable over the sub-tropical South Pacific (Figure 2).
Above normal rainfalls are highly probable in the equatorial Pacific in Kiribati, Republic of the Marshall Islands, Tuvalu and Tokelau, while below normal precipitation is expected over the northern maritime continent and adjacent seas in Vanuatu, Solomon Islands, Fiji, Samoa, Tonga, American Samoa and Cook Islands. The forecasts for March-April-May (MAM) 2016 suggest weakening of the El Niño episode with weakening of the above-normal rainfall anomalies in the equatorial Pacific surrounded by the areas of below normal precipitation.
Download full Outlook here [2015 DJFMAM] Outlook-final.pdf
Figure 1: Seasonal mean anomalies of the observed surface air temperature (1 September – 9 November 2015).
Figure 2: Deterministic MME seasonal 2m temperature forecast for December 2015 - February 2016.
Figure 3: Deterministic MME seasonal rainfall forecast for December 2015 - February 2016.