This is the world sea-surface anomaly from January 10th, 2008, showing negative sea-surface anomalies extending throughout much of the eastern and central equatorial Pacific, right up to the South American coast.

Here is the latest world sea-surface anomaly image (Feb 18th, 2008). Note: the colder anomalies have moved westward away from South America.

There are now some subtle hints that the La Nina conditions (colder than normal sea surface water temperatures) across the equatorial Pacific may have peaked in intensity. The latest oceanic index value from NOAA for the (NOV/DEC/JAN) time period was a -1.4. A number less than -0.5 for a three consecutive running mean is characterized as a La Nina, while a number above 0.5 is considered an El Nino.

Sea surface water temperatures across the central and western equatorial Pacific are still solidly below normal, but positive anomalies have recently begun to show up in the eastern (1+2 nino) region near the west coast of South America, and this "may" already be having some impact on the overall weather pattern across North America.

The latest IRI experimental ensemble SST forecast for the Nino 3 region, which covers the eastern half of the equatorial Pacific, is forecasting sea surface temperature anomalies to be back to normal by early summer, if not slightly above. This is certainly an upward trend compared to what it was forecasting back in January. Now, as I have said in the past, the track record of these forecasts is nothing great, and this particular one is experimental, but I think it is on to something as it is common to see these La Nina's peak out by late in the winter. It will be interesting to see what actually happens through the spring.

Here is that new IRI forecast.......