UPDATE: There’s some question about NCEP’s communications intent with this paper. While they cite “La Niña conditions” in the language, and the visual imagery lends itself to that, the numerical threshold of ONI hasn’t been reached, as has been pointed out in comments. Yet NCEP made no mention in the summary that the threshold had not been reached. I’ll see if I can locate the authors and get a clarification. – Anthony
In a document published January 19th, NOAA’s Climate Prediction Center (NCEP) has officially put the stamp on the cold water conditions we’ve seen growing in the equatorial mid and eastern Pacific. I first reported on this on December 4th, 2008. This does not bode well for California’s drought conditions, which are likely to continue due to this renewed La Niña event.
Sea Surface Temperatures as of January 5th, 2009. Click for a larger image
In the document, which you can see here, NCEP says:
•Atmospheric and oceanic conditions reflect La Niña.
•Negative equatorial SST anomalies persist across the central and eastern Pacific Ocean.
•Based on recent trends in the observations and model forecasts,La Niña conditions are likely to continue into Northern Hemisphere Spring 2009.
Here is a map provided that shows the precipitation departure for the last 90 days. Note that while the Pacific northwest (notably Seattle) is taking a bath, California gets nearly nothing. The jet stream pattern has been pushed far north this past year.
I also found this time series graph of equatorial Pacific ocean heat content anomaly for 180 to 100 degrees west of particular interest:
They also say that:
A majority of ENSO forecasts indicate below-average SSTs in the central equatorial Pacific through Northern Hemisphere Summer 2009, with about half of the models suggesting La Niña conditions will continue through February-March-April 2009.
Place your bets now.
There is also a wealth of information in the PDF document NCEP has prepared. I’m sure our readers can draw some interesting conclusions and analyses from it.
A hat tip to WUWT reader Alan Wilkinson for bringing the NCEP document to my attention.