HIGHLIGHT: The seasonal mean NINO3.4 anomaly was -1.0 C for DJF2012, unchanged from NDJ.

The CA method, acting on global DJF2012 seasonal means as latest input, has all of its members on the cold side of neutral thru FAM 2012. By MAM 2012 all members are in neutral territory. Some members crawl hesitantly into positive territory by summer 2012. Although the ensemble mean is positive from MJJ onward no members go for an El Nino (>+0.5) at any time later in 2012 or 2013.

Weights have changed for two reasons. The first is that weights from last month, even if persistent, have shifted forward into the next year in the Table below. For instance the +17 assigned to 1999 one month ago is now evolved to +22 assigned to 2000. More importantly, we have increased the size of the covariance matrix by one from 54 to 55. This results in a re-arrangement because of co-linearity among the years (very few are naturally orthogonal).

There are five (somewhat recent) years with high +ve weight!, and also five (somewhat older) years with high -ve weight. OCN flavor is much reduced compared to a few years ago.

Table 1. Inner products (IP; scaled such that the sum of absolute values is 100; not shown) and weights (Wgt multiplied by 100.) of each of the years to construct an analogue to the sequence of 12 consecutive overlapping 3-month periods defined as the base (currently the 12 overlapping seasons string JFM2011 thru DJF2012). Years in the table are labeled by the year of the middle month of the most recent predictor season. Weights for 1956 and 2011 are less (by 50%) because only half the members use these years ("early" members use 1956, "late" members 2011). Data currently thru Feb 2012.

Year	IP	Wgt	Year	IP	Wgt	Year	IP	Wgt	Year	IP	Wgt	Year	IP	Wgt	Year	IP	Weigt
1956	xx	0	1966	xx	-9	1976	xx	5	1986	xx	-1	1996	xx	-7	2006	xx	-3
1957	xx	3	1967	xx	-5	1977	xx	2	1987	xx	-12	1997	xx	10	2007	xx	10
1958	xx	1	1968	xx	-1	1978	xx	6	1988	xx	-15	1998	xx	1	2008	xx	8
1959	xx	-5	1969	xx	-13	1979	xx	6	1989	xx	-4	1999	xx	-3	2009	xx	13
1960	xx	2	1970	xx	4	1980	xx	-1	1990	xx	11	2000	xx	22	2010	xx	-4
1961	xx	-6	1971	xx	1	1981	xx	-2	1991	xx	-1	2001	xx	6	2011	xx	9
1962	xx	3	1972	xx	4	1982	xx	-1	1992	xx	-5	2002	xx	9	2012	xx	NA
1963	xx	4	1973	xx	1	1983	xx	7	1993	xx	-9	2003	xx	-8		xx	Xx
1964	xx	7	1974	xx	-2	1984	xx	7	1994	xx	-10	2004	xx	-9		xx	Xx
1965	xx	-2	1975	xx	1	1985	xx	-12	1995	xx	1	2005	xx	1		xx	Xx

Weights are high +ve (>+0.10) for 2009,2007,2000,1997,1990

Weights are high -ve (< - 0.10) for 1994,1988,1987,1985,1969

Ens ave Nino34 anomaly forecasts, for leads -3, -2, -1, 0 etc: in plain numbers (ensemble mean):

-0.99	-0.93	-0.73	-0.36	-0.12	0.06	0.15	0.15	0.12	0.1	0.09	0.14	0.17	0.24	0.16	0.08	-0.01	0.01	0.01	0.01	0
	JFM12		MAM		MJJ		JAS		SON		NDJ		JFM13		MAM		MJJ		JAS

One month ago:

-1	-1	-0.95	-0.72	-0.51	-0.3	-0.11	0.01	0.03	0.02	0.02	0.02	0.09	0.2	0.28	0.23	0.21	0.18	0.24	0.25	0.25
NDJ		JFM12		MAM		MJJ		JAS		SON12		NDJ		JFM13		MAM		MJJ		JAS

Two months ago:

-1.01	-1.01	-1.04	-1.01	-0.83	-0.65	-0.46	-0.27	-0.17	-0.15	-0.18	-0.15	-0.13	0.05	0.14	0.23	0.17	0.12	0.07	0.1	0.11
	NDJ		JFM12		MAM		MJJ		JAS		SON		NDJ		JFM13		MAM		MJJ
Three months ago: -0.89	-0.87	-0.89	-0.94	-0.92	-0.77	-0.6	-0.44	-0.29	-0.24	-0.26	-0.32	-0.31	-0.07	0.08	0.21	0.3	0.25	0.21	0.16	0.18
SON11		NDJ		JFM		MAM12		MJJ		JAS		SON		NDJ		JFM13		MAM		MJJ

Four months ago:

-0.76	-0.76	-0.75	-0.78	-0.79	-0.76	-0.63	-0.48	-0.35	-0.23	-0.22	-0.28	-0.36	-0.17	-0.08	0.07	0.22	0.3	0.26	0.24	0.23
	SON11		NDJ		JFM12		MAM		MJJ		JAS		SON12		NDJ		JFM13		MAM

Anomalies relative to 1981-2010 climo, as of the May 2011 release. Older forecasts (previous to May 2011 release) are relative to 71-2000