ENSO Watch: 65% Chance of El Nino by end of 2012
Posted 06 July 2012 - 07:16
Posted 12 August 2012 - 08:54
Posted 05 October 2012 - 14:37
Posted 14 March 2013 - 11:01
From July to October 2012, sea surface temperatures increased to a borderline El Niño level, but the atmospheric characteristics of El Niño failed to develop and the ocean-atmosphere
system as a whole remained in a neutral state. Since November the tropical Pacific Ocean has cooled, and although the first two months of 2013 showed patterns of ocean temperatures that approached borderline La Niña levels, and cloudiness and trade winds that also leaned towards La Niña conditions, the tendency has been weak and the state of the ocean-atmosphere system as a whole continued to be neutral.
Posted 14 March 2013 - 12:06
Now that the unusual Low that had plagued the SE N. Pacific seems to have moved off, the Eastern Pacific off the western Central American coast appears to be re-warming. The ITCZ continues to expand the West African heat across the southern N. Atlantic, spilling out over the Eastern Pacific. Though, the PDO continues to suggest La Nina conditions, with a large cold pool of SSTs off the Western N. American continent, there is a strong warming Anomolie sitting off the Chinese coast. If the Walker circulation were to breakdown this warm pool of water would rapidly fill to the East and likely shift the PDO positive.
Part of the confounding influence is the cold pool in the Southern Pacific. Similar to 2003 we again have the bi-polar/mirror or neutral conditions between the N. and S. Pacific. The main difference is the atmospheric conditions remain in the La Nina phase, as opposed to the 2003 El Nino.
The conditions do point to the potential for a phase shift; however, as in the past 10 years the overwhelming atmospheric circulation of a far North Sub-Tropical Jet Stream and a wildly meandering Polar Jet Stream suggests, there will not be a phase change before June. (A strong El Nino SST pattern would be required to outlast the anti-El Nino influence of the Southern Hemispheric Winter.) If we see another Summer like last or a similar atmospheric heat dump towards the North Pole like in the 2004-2005 transition, we could expect a phase shift as early as Spring 2014. Though it is more likely going to have to wait till 2015 to see the ENSO phase change.
The March position of the Sub-Tropical Jet across the southern N. American region in the Feb.-Apr. timeframe will be one of the better atmospheric indicators. Also, the satellite water vapor images should suggest a very good optical depth below 30 deg. N down to near 10 deg. N. If you watch the daily temperatures in the US SW and you daily see 90F plus (32C+) by the end of Mar. to early Apr., its time to batten the hatches and fill the water barrels...
PS: 2014 maybe a possibility, Tucson, AZ today 91F, tomorrow 92F, (though the highs are mid-80s the next 5 days). Should be an interesting watch...