Latest ENSO forecasts: +0.3C average for Niño 3.4 during approaching boreal winter (2012-2013) – Australia and New Zealand will have driest summer in years

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.

El Niño winter forecasts IRI ensemble
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.

El Niño forecast Australia & New Zealand 2012-2013
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 |

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