Cooling of mid-Pacific ocean temperatures is a welcome development but so far it is just an interesting change worth keeping an eye on, rather than an opportunity to significantly alter production plans.

'It is too early to know if the cooling trend in this region will continue to develop into a strong La Nina effect,' says NSW Department of Primary Industries climatologist, Paul Carberry.

Current summaries of mid-Pacific sea surface temperatures show a large area of slightly below average temperature water along the equator.

'This is as close as we have been to a genuine La Nina since 1999,' said Mr Carberry.

Changes in temperatures here can develop quickly in the April to May period and they do go either way.

'Most of NSW has a much better chance of getting good winter and spring rainfall when there is a La Nina but there is practically no connection with autumn rainfall.

'While the chances of good winter spring rain are better, there is always some small risk of just average or even a bit below,' Mr Carberry said.

The internet is the easiest way of checking what is going on and the website http://iri.columbia.edu/climate/ENSO/currentinfo/QuickLook.html provides a good summary.

Detailed weekly analysis of temperatures in the region can be seen at http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstweek_c.gif.

- RON AGGS

This story appears in Agriculture Today.