HIGHLIGHT: The seasonal mean NINO3.4 anomaly was about -0.12 C for FMA2013, up from JFM2013 (-0.40).
The CA method, acting on global FMA2013 seasonal means as latest input, but using a string of global SST going back one year, has all of its members staying negative for Nino34 but in the neutral zone until JAS. By the fall of 2013 most of its members are <-.5 but none <-1.0. A weak cold event! Warmer than last month because April broke the cooling trend we saw before.
Weights have changed little from last month for most years except a few big weights that went down. Note that 1997 had an ominous weight of -14, contributing to a cold forecast until one month ago, but the weight dropped to -7. 1987 (thru December that particular past situation was labeled 1986) has been holding on to a large negative weight for a whole year: since spring 2012.
OCN flavor is much reduced compared to a few years ago, but not completely gone. The only large +ve weights are in the last 10 years. 1986-1997 is solidly negative.
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 MAM2012 thru FMA2013). Years in the table are labeled by the year of the middle month of the most recent predictor season. Weights for 1956 and 2012 are less (by 50%) because only half the members use these years ("early" members use 1956, "late" members 2012). Data currently thru April 2013.
Year |
IP |
Wgt |
Year |
IP |
Wgt |
Year |
IP |
Wgt |
Year |
IP
|
Wgt |
Year |
IP |
Wgt |
Year |
IP |
Weigt |
1956 |
xx |
0 |
1966 |
xx |
5 |
1976 |
Xx |
-3 |
1986 |
xx |
-11 |
1996 |
xx |
-7 |
2006 |
xx |
1 |
1957 |
xx |
5 |
1967 |
xx |
0 |
1977 |
Xx |
1 |
1987 |
xx |
-13 |
1997 |
xx |
-7 |
2007 |
xx |
12 |
1958 |
xx |
0 |
1968 |
xx |
1 |
1978 |
Xx |
5 |
1988 |
xx |
5 |
1998 |
xx |
1 |
2008 |
xx |
13 |
1959 |
xx |
1 |
1969 |
xx |
-6 |
1979 |
Xx |
7 |
1989 |
xx |
-4 |
1999 |
xx |
-1 |
2009 |
xx |
8 |
1960 |
xx |
-5 |
1970 |
xx |
2 |
1980 |
Xx |
2 |
1990 |
xx |
3 |
2000 |
xx |
2 |
2010 |
xx |
4 |
1961 |
xx |
-6 |
1971 |
xx |
-3 |
1981 |
Xx |
-2 |
1991 |
xx |
-3 |
2001 |
xx |
4 |
2011 |
xx |
-1 |
1962 |
xx |
9 |
1972 |
xx |
2 |
1982 |
Xx |
-3 |
1992 |
xx |
-7 |
2002 |
xx |
8 |
2012 |
xx |
10 |
1963 |
xx |
5 |
1973 |
xx |
-3 |
1983 |
xx
|
-5 |
1993 |
xx |
-5 |
2003 |
xx |
8 |
2013 |
xx |
NA |
1964 |
xx |
4 |
1974 |
xx |
-12 |
1984 |
Xx |
5 |
1994 |
xx |
-4 |
2004 |
xx |
-4 |
xx |
Xx |
|
1965 |
xx |
2 |
1975 |
xx |
-5 |
1985 |
Xx |
2 |
1995 |
xx |
-2 |
2005 |
xx |
1 |
xx |
Xx |
Weights are high +ve (>+0.10) for 2012, 2008,2007
Weights are high -ve (< - 0.10) for 1986,1987,1974
Ens ave Nino34 anomaly forecasts, for leads -3, -2, -1, 0 etc: in plain numbers (ensemble mean):
-0.29 |
-0.31 |
-0.34 |
-0.32 |
-0.27 |
-0.29 |
-0.35 |
-0.38 |
-0.41 |
-0.48 |
-0.58 |
-0.58 |
-0.51 |
-0.35 |
-0.2 |
0.02 |
0.16 |
0.19 |
0.18 |
0.25 |
0.41 |
MAM13 |
MJJ |
JAS |
SON |
NDJ |
JFM |
MAM14 |
MJJ |
JAS |
SON |
One month ago:
-0.41 |
-0.4 |
-0.46 |
-0.58 |
-0.6 |
-0.61 |
-0.68 |
-0.8 |
-0.88 |
-0.93 |
-0.99 |
-1.09 |
-1.01 |
-0.83 |
-0.56 |
-0.23 |
0.13 |
0.39 |
0.42 |
0.46 |
0.57 |
JFM13 |
MAM |
MJJ |
JAS |
SON |
NDJ |
JFM14 |
MAM |
MJJ |
JAS |
SON |
Two months ago
-0.38 |
-0.38 |
-0.42 |
-0.5 |
-0.52 |
-0.5 |
-0.49 |
-0.59 |
-0.71 |
-0.77 |
-0.77 |
-0.79 |
-0.85 |
-0.75 |
-0.6 |
-0.36 |
-0.04 |
0.31 |
0.59 |
0.64 |
0.67 |
JFM13 |
MAM |
MJJ |
JAS |
SON13 |
NDJ |
JFM14 |
MAM |
MJJ |
JAS14 |
Three months ago
-0.01 |
-0.03 |
-0.11 |
-0.22 |
-0.22 |
-0.16 |
-0.11 |
-0.1 |
-0.19 |
-0.28 |
-0.25 |
-0.19 |
-0.15 |
-0.14 |
-0.17 |
-0.18 |
-0.08 |
0.1 |
0.32 |
0.48 |
0.48 |
NDJ |
JFM13 |
MAM |
MJJ |
JAS |
SON13 |
NDJ |
JFM14 |
MAM |
MJJ |
JAS |
Four months ago:
0.18 |
0.2 |
0.16 |
0.05 |
-0.02 |
-0.03 |
-0.02 |
-0.02 |
-0.06 |
-0.18 |
-0.27 |
-0.24 |
-0.16 |
-0.14 |
-0.14 |
-0.15 |
-0.12 |
0.02 |
0.19 |
0.34 |
0.41 |
NDJ |
JFM13 |
MAM |
MJJ |
JAS |
SON13 |
NDJ |
JFM14 |
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