Over the past few years, we’ve seen historically strong La Nina conditions in the eastern Pacific. These conditions affect growing seasons and weather patterns around the world and, combined with human global warming, have been a contributor to drought conditions in the US.
This year, forecasters predicted a reappearance of El Nino (warming waters in the Eastern Pacific as opposed the the cooling waters that represent La Nina). But the warming that occurred in this critical region was very weak. Now, a few cool patches have again developed over the eastern Pacific, begging the question — is another La Nina emerging?
These cool patches are, currently, rather small and disperse, but consistent growth could result in another La Nina after two following 2010 and 2011. Such an event would likely mean a continued intensification of US drought even as another year of record-breaking worldwide temperature highs may be put off to 2013 or 2014. It currently appears 2012 may be in the range of 7-10th hottest on record and another La Nina in 2013 could hold it in that range as well.
The heat map itself shows a strange trend in which the Northern Atlantic, the Arctic Ocean, the Pacific region near Japan, and the Mediterranean all show water temperatures very high above average with widespread milder, but still above average, zones throughout the southern hemisphere. Only two regions — the Pacific Ocean around Alaska and the Pacific east of Hawaii — showed significant below average readings. And, as mentioned before, little cool blips are starting to show up in a region that typically spawns La Nina/El Nino.