That means for this equatorial Pacific region* during the 2012-2013 winter temperatures are not sufficiently elevated to meet the criterion for a proper El Niño.

[*) In other East Pacific regions this could be different – although at present for instance the Peruvian coastal waters [Niño 1 & 2] do not show much of that classical Christmas activity. This may swing quickly though.]

In the model ensemble of the International Research Institute for Climate and Society (IRI) shown in the graph below there is a high level of agreement that ENSO will remain somewhere in the range between El Niño (>0.45C) and neutral (0C anomaly) for several months ahead.

he highest member is presented by the Scripps institution of Oceanography’s climate model, which forecasts a +1 degrees Celsius temperature anomaly for Niño 3.4 as average over the months of December 2012 and January and February 2013 – a strong El Niño scenario.

The only negative member is forecast by NOAA’s NCEP CFSv2, which makes a bit a strange deep sweep (even temporarily touching La Niña (-0.45C) by February 2013) ending up in the high range by the end of the boreal spring.

There is one really safe conclusion to make from the IRI ensemble forecast: no one (ignoring that sweeping run of NCEP CFS) says La Niña for a long time ahead.

Summer forecast Australia: floods, no – drought, yeah

Of course when it comes to SST anomalies an actual observations chart has more to say than a predictions graph without any geographical spread. Shown below is the current Pacific sea surface temperature anomaly chart by NOAA.

If there would be news in this for anyone it should be for the Australians. Queensland and the Northern Territory will experience the weakest monsoon in years [Western Australia could be a different story].

The Australian summer of 2010-2011 brought extreme rainfall and floods to Queensland and New South Wales – and also in 2011-2012 monsoon and summer rainfall were above average. In both instances this was caused by positive temperature anomalies in the Coral Sea (and elsewhere in the West Pacific) – schoolbook example of La Niña pattern – which fueled the ITCZ, which is annually set to make landfall over north-eastern Australia somewhere around December.

Although there is nothing schoolbook about this year’s El Niño [it is mixed up with weak waves and remnants of La Niña, see North Pacific] – probably the only region (globally) that may face classical consequences (not Peru, not the US and – our misjudgement – probably also not Indonesia) is Australia, including New Zealand.

For Queensland this is probably good news – a far smaller risk of flooding. For New South Wales opposite problems are quite likely to arise: drought, smaller harvest of wheat and other crops, possibly wildfires.

Clear-blue-sky summer for New Zealand

The negative SST anomalies of the Coral Sea extend to the South and Southeast and are even stronger in the Tasman Sea (-1 to -2C). Also North, East and Southeast (not Soutwest) of New Zealand temperatures the sea water is relatively cool – presenting high likelihood for dominant high pressure weather systems to settle over New Zealand during the approaching southern hemisphere summer months.

So to generalise* an entire season for an entire country: if you live in New Zealand, expect more sun and less rain than usual.

[*) If somewhere along these months your barbeque guests would happen to get soaked anyway because half a planet away we did not foresee that local storm of January 14 – please do blame us. In fact, we have a Facebook for all your comments.]

© Rolf Schuttenhelm | www.bitsofscience.org