Island Climate Update 75 - December 2006

The Brief La Niña of 2005-06 and the El Niño of 2006-07
Anthony G. Barnston, International Research Institute for Climate and Society (IRI)
Figure 1. Time-longitude section of zonal wind anomaly and SST anomaly
Historically since 1950, ENSO episodes have tended to occur with approximately one-year duration, often beginning near April-July of one year and ending near March-May of the following year. Exceptions have occurred.

An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region.
Number 75 – December 2006
November’s climate
‘Yani’, the second tropical cyclone of the season
Moderate El Niño persists in the Pacific
Enhanced convection persists west of the Date Line, suppressed convection between the Northern Cook Islands and the Pitcairn Island
Warmer than normal in parts of Fiji and New Caledonia, cooler in parts of southern French Polynesia
El Niño

Climate developments in November 2006
Outgoing Long-wave Radiation anomalies for November 2006. (Click for enlargement and detail)
Enhanced convection occurred during November, mainly west of the Date Line, from the north of New Caledonia north east to Western Kiribati, including Vanuatu, the southeast of the Solomon Islands, and Tuvalu, although not as strong as in October. Some of the convection over the Solomon Islands and Vanuatu was associated with the passage of tropical cyclone "Yani", the second tropical cyclone this season.

Tropical rainfall outlook: December 2006 to February 2007
Rainfall outlook map for December 2006 to February 2007. (Click for enlargement)
Rainfall forecasts for the Pacifi c region clearly exhibit El Niño patterns for the coming three months, December 2006 to February 2007.
Enhanced convection is expected in the equatorial region of Western and Eastern Kiribati, Tuvalu, and Tokelau where rainfall is forecast to be above average.

Tropical Pacific rainfall - November 2006
Territory and station name
October 2006 rainfall
total (mm)
October 2006 percent
of average
Australia
Cairns Airport
28.0
29
Townsville Airport
0.4
1
Brisbane Airport
56.4
58
Sydney Airport
29.2
35
Cook Islands
Penrhyn
187.6
83
Rarotonga Airport
93.9
69
Fiji
Rotuma
456.7
162
Udu Point
58.3
29
Nadi
120.1
91
Nausori
277.0
113
Ono-I-Lau
32.2
28
French Polynesia
Hiva Hoa, Atuona
28.8
30
Bora Bora Motu
152.8
84
Tahiti – Faa’a
37.4
29
Tuamotu, Takaroa
98.4
47
Gambier, Rikitea
79.2
35

Sources of South Pacific rainfall data
This bulletin is a multi-national project with important collaboration from the following Pacific nations:
American Samoa
Australia
Cook Islands
Fiji
French Polynesia
Kiribati
New Caledonia
New Zealand
Niue
Papua New Guinea
Pitcairn Island
Samoa
Solomon Islands
Tokelau
Tonga
Tuvalu
Vanuatu
Requests for Pacific island climate data should be directed to the Meteorological Services concerned.
Acknowledgements
This bulletin is made possible with financial support from the New Zealand Agency for International Development (NZAID), Wellington, New Zealand, wi