HIGHLIGHT: The seasonal mean NINO3.4 anomaly was -0.8 C for JFM2012, down from NDJ (-1.0).
The CA method, acting on global JFM2012 seasonal means as latest input, has all of its members on the cold side of neutral thru MAM 2012. By AMJ 2012 all members are in neutral territory. Some members crawl hesitantly into positive territory by summer 2012. No members go for an El Nino (>+0.5) at any time later in 2012 or 2013. One member is ‘hanging back’ and going into a 3rd year in arrow La Nina, albeit very weak.
Weights have changed. Recall, we have increased the size of the covariance matrix by one from 54 to 55 one month ago. This results in a re-arrangement because of co-linearity among the years (very few are naturally orthogonal). Year 2000 carries a +0.24 weight, which is high in the business of a constructed analogue (a natural analogue would have weight 1.00; all other years 0.).
There are four (somewhat recent) years with high +ve weight!, and six (somewhat older) years with high -ve weight. OCN flavor is much reduced compared to a few years ago, but not completely gone.
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 FMA2011 thru JFM2012). 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 Mar 2012.
Year |
IP |
Wgt |
Year |
IP |
Wgt |
Year |
IP |
Wgt |
Year |
IP
|
Wgt |
Year |
IP |
Wgt |
Year |
IP |
Weigt |
1956 |
xx |
0 |
1966 |
xx |
-11 |
1976 |
xx |
1 |
1986 |
xx |
-6 |
1996 |
xx |
-9 |
2006 |
xx |
-5 |
1957 |
xx |
6 |
1967 |
xx |
-3 |
1977 |
xx |
3 |
1987 |
xx |
-11 |
1997 |
xx |
2 |
2007 |
xx |
12 |
1958 |
xx |
1 |
1968 |
xx |
-3 |
1978 |
xx |
7 |
1988 |
xx |
-11 |
1998 |
xx |
-1 |
2008 |
xx |
9 |
1959 |
xx |
0 |
1969 |
xx |
-11 |
1979 |
xx |
6 |
1989 |
xx |
2 |
1999 |
xx |
-2 |
2009 |
xx |
13 |
1960 |
xx |
3 |
1970 |
xx |
0 |
1980 |
xx |
3 |
1990 |
xx |
3 |
2000 |
xx |
24 |
2010 |
xx |
-8 |
1961 |
xx |
-3 |
1971 |
xx |
-4 |
1981 |
xx |
-3 |
1991 |
xx |
1 |
2001 |
xx |
9 |
2011 |
xx |
7 |
1962 |
xx |
8 |
1972 |
xx |
6 |
1982 |
xx |
-3 |
1992 |
xx |
1 |
2002 |
xx |
6 |
2012 |
xx |
NA |
1963 |
xx |
6 |
1973 |
xx |
1 |
1983 |
xx
|
7 |
1993 |
xx |
0 |
2003 |
xx |
-8 |
xx |
Xx |
|
1964 |
xx |
5 |
1974 |
xx |
-5 |
1984 |
xx |
11 |
1994 |
xx |
-10 |
2004 |
xx |
-4 |
xx |
Xx |
|
1965 |
xx |
-2 |
1975 |
xx |
4 |
1985 |
xx |
-12 |
1995 |
xx |
-7 |
2005 |
xx |
1 |
xx |
Xx |
Weights are high +ve (>+0.10) for 2009,2007,2000,1984
Weights are high -ve (< - 0.10) for 1994,1988,1987,1985,1969,1966
Ens ave Nino34 anomaly forecasts, for leads -3, -2, -1, 0 etc: in plain numbers (ensemble mean):
-0.82 |
-0.72 |
-0.49 |
-0.14 |
-0.02 |
0.01 |
-0.03 |
-0.1 |
-0.16 |
-0.19 |
-0.15 |
-0.11 |
-0.01 |
0.02 |
0.01 |
-0.05 |
-0.04 |
-0.01 |
-0.02 |
-0.02 |
-0.01 |
JFM12 |
MAM |
MJJ |
JAS |
SON |
NDJ |
JFM13 |
MAM |
MJJ |
JAS |
SON |
One month ago:
-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 |
Two months 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 |
Three 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 |
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Four 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 |
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Anomalies relative to 1981-2010 climo, as of the May 2011 release. Older forecasts
(previous to May 2011 release) are relative to 71-2000