background image
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Cloudiness  around the Equatorial Pacific and near the Dateline has been generally higher than average since August and 
there has been a trend of increasing cloudiness since late May. This pattern is keeping the reduced or weaker than normal 
Trade Winds and increasing ocean temperatures near the Dateline and in the central Equatorial Pacific. 
 
 
In Brief 
 
Current Situation  
• 
SST 
• 
SOI 
• 
Cloudiness  
• 
Observations in 
Fiji 
 
Outlook 
 
Cyclone Season 
 
ENSO & El Niño 
 
 
Issue 02 
November 2006 
 
 
Climate  
Services  
Division 
 
In Brief 
 
• 
An El Niño has now established in the tropical Pacific basin; 
 
• 
Key El Niño Southern Oscillation (ENSO) indicators show intensifi-
cation towards a moderate event and continue into early 2007; 
 
• 
Observed trend show below average rainfall in parts of the country; 
 
• 
Given the strengthening El Niño conditions, increasing trend to-
wards below average rainfall is likely in the coming months; 
 
• 
There is increased risk of cyclones for countries near and east of 
Dateline including Fiji. 
By September, climate patterns across the Equatorial Pacific resembled a developing 
El Niño conditions in the region. In 
response, Fiji Meteorological Service issued an ENSO Update indicating that there was a possibility of developing a “
weak 
to moderate” basin-wide El Niño and that it could persist into early 2007. Conditions since the last update have reinforced 
the event with recent observations confirming that an 
El Niño has been established across the tropical Pacific basin with 
signs of intensifying into a moderate event.  
Sea Surface Temperatures (SST’s) 
 
SST’s continued to warm in the Equatorial Pacific especially near 
the Dateline and in the Central Pacific. The Central and Western 
Pacific is about 1.0 to 1.5˚C warmer than normal in October with 
most of the warming taking place from August to October. A patch 
of negative anomaly has appeared in the Western Pacific near Solo-
mon Islands. The sub-surface temperatures have also increased be-
low the depth of 100 meters  and continued to propagate eastwards. 
Source: BOM 
The Southern Oscillation Index (SOI) 
 
SOI has been negative for the past consecutive six months with Oc-
tober value being –15.3. Since May the values have been -10, -6 and 
-9 for May, June and July respectively. The SOI continued to fall in 
August with a value of –16 and it temporarily rose in September to  
–5.1 and fell again in October. The 5-month running mean centred 
on August is –10, a point below last month. The 3 month running 
mean  centred on September is –12.  
 
Given the historic precedence, the SOI is very likely to remain nega-
tive for the rest of 2006. 
S o u t h e r n   Osc i l l a t i o n   I n d e x   Vs  5 - M o n t h  R u n n i n g   M e a n  
( J a n u a r y   2 0 0 4   -   Oc t o b e r   2 0 0 6 )
-35. 0
-25. 0
-15. 0
-5. 0
5. 0
15. 0
25. 0
35. 0
M o n t h / Ye a r
SOI
5 M ont h Runni ng M ean
Current Situation - SST, SOI and Cloudiness  
Source: FMS 
El Niño is back 
in  
the Region.  
Parts of Tavua 
(Yaqara) in 2002/03 
“
weak El Niño”. 
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Observations in Fiji show parts of the country already having an El Niño effect in terms of generally reduced rainfall with 
the increasing trends toward below average rainfall.  This is largely due to the South Pacific Convergence Zone (SPCZ) re-
maining to the north of the Group and absence of general organized weather patterns affecting the country. Although there had 
been a few rainfall events, these were very localized and were not sufficient, resulting in some parts of Western Viti Levu, 
Northern Vanua Levu and some smaller islands experiencing less than normal rainfall. The effect of below average rainfall 
and dry spells has been more pronounced in Northwestern parts of Viti Levu, some areas in Vanua Levu and now extending to 
other parts of Viti Levu and outer islands in the Yasawa, Mamanuca and the Lau Groups. More recently (mid October to late 
November) rainfall had been negligible in many parts of the country resulting in about 70% of the reporting sites experiencing 
well below average (<40%) rainfall.  
 
 
 
 
 
 
 
 
 
For more information, contact: 
Fiji Meteorological Service, Private Mail Bag NAP0351, Nadi Airport. Phone : 6724888, Fax : 6720430. Visit website at http:/www.met.gov.fj for other 
products and services. E-mail : fms@met.gov.fj or climate@met.gov.fj.  
All correspondences must be addressed to the Director of Meteorology. 
Page 2 
November 2006 
 
Outlook 
2006/2007 Cyclone Season  
ENSO & El Niño 
ENSO stands for El Niño Southern Oscillation and refers to an irregular cycle of  warming and cooling of the SST of the 
Tropical Pacific Ocean whose extremes are known as El Niño (warming) and La Nina (cooling). 
 
The term “El Nino” was given to a local warming of the ocean near the Peruvian coast in South America that appeared 
around Christmas. Scientists now refer it to a sustained warming over a large part of Central and Eastern Tropical Pacific 
Ocean. It usually occurs every 3 to 7 years and is characterized by shifts in normal weather and climate patterns. During 
El Niño events, SST’s in the Central and Eastern Tropical Pacific Ocean become significantly higher than normal.  These 
temperature changes are strongly linked to major climate fluctuations in the region and once initiated, such events can 
last for twelve months or more, impacting the climate patterns globally, regionally and locally.  
The emergence of a “weak El Niño” in the region and with the prediction for it to intensify into a moderate event should sig-
nificantly affect tropical cyclone formation, frequency and distribution within the South Pacific region and beyond. Above 
average number of tropical cyclones are expected with greater tendency for them to form near and east of the Dateline. Coun-
tries like Fiji, Niue, Tonga, Samoa and Southern Cooks in particular have an increased risk of being affected this season. 
The chance for a hit is high during El Niño conditions with an increased risk of a cyclone affecting Fiji this season compared 
to last season. As predicted, cyclone season started early with a pre-season “TC Xavier” forming against all odds near Solo-
mon Islands during later half of October.  Models indicated a southwest curve towards Vanuatu but drifted south and later 
southeast curving towards Fiji, however, the system dissipated before reaching close proximity to the country. Since 1969/70 
season, 2 cyclones have affected Fiji in November and 10 in December. During El Niño seasons for the same period, none 
have affected in November and one in December. The chances of being affected in November and December is rather low 
however the chances are higher from January to March 2007. 
A consensus has been reached that a basin wide “El Niño” has been established in the region with strengthening signs to-
wards moderate event. Most of the statistical and coupled climate predictions model indicate for it to persist into early 2007 
with Pacific ocean temperatures to peak around January or February. Although Wet Season has commenced, the effect of El 
Niño is likely to suppress peak Wet Season rainfall and cause warmer than normal temperatures generally from December to 
February. This means that rainfall is expected to remain variable with a trend towards below average rainfall. This trend is 
expected to continue and extend to most parts of the country, unless severe weather such as tropical cyclone or tropical de-
pression affects or passes close to the country. Given that rainfall is likely to be below average, the amounts could generally 
be sufficient to keep soil moisture levels adequate but likely to cause water stress for drinking and short term crops.  Fiji Me-
teorological Service will continue to monitor the situation and provide updates as and when necessary.