HIGHLIGHT: The seasonal mean NINO3.4 anomaly was 0.0C for MJJ2016, down from AMJ (0.5) and the first time a 3-mo mean was zero in a long time. We have ended the 15/16 warm event.
The CA method, acting on global MJJ2016 seasonal means as latest input, but using a string of global SST going back one year, shows a significant cool down predicted in 2016 by half the members. Half the members are colder than -0.5 by late 2016. But the solution is like a bifurcation, with all members that look back only 1 season staying positive or near zero, and all members that look back 4 non-overlapping seasons going negative.
There are 6 (4) large +ve (-ve) weights in excess of abs(0.10), listed below.
Weights changed modestly from last month. The weight for 1998, in the aftermath of a previous big warm event in a large 0.23. The weight for 2015 (the string ending with MJJ2015) is still high even if it has decreased some, and this puts a damper (according to CA-SST as designed) on the possibility for a La Nina for later on in 2016, but only for the 6 “late” members of the ensemble of 12. The weight for 2015 should go down dramatically if neutral or cold conditions develop and persist. Some sort of non-linearity and an oddity related to the spring transition. 2014 (a failed warm event of sort) also has a high weight and even higher when 2015 is not included. Some of the high weight for 2014 and 2015 is non-ENSO, but interdecadal or global warming like.
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 JJA2015 thru MJJ2016). Years in the table are labeled by the year of the middle month of the most recent predictor season. Weights for 1956 and 2015 are less (by 50%) because only half the members use these years ("early" members use 1956, "late" members 2015). Data currently thru July 2016.
Year |
IP |
Wgt |
Year |
IP |
Wgt |
Year |
IP |
Wgt |
Year |
IP |
Wgt |
Year |
IP |
Wgt |
Year |
IP |
Weigt |
1956 |
xx |
-6 |
1966 |
Xx |
-8 |
1976 |
Xx |
-7 |
1986 |
xx |
3 |
1996 |
xx |
-7 |
2006 |
xx |
-4 |
1957 |
xx |
6 |
1967 |
Xx |
-11 |
1977 |
Xx |
1 |
1987 |
xx |
-5 |
1997 |
xx |
1 |
2007 |
xx |
3 |
1958 |
xx |
10 |
1968 |
Xx |
9 |
1978 |
Xx |
3 |
1988 |
xx |
5 |
1998 |
xx |
23 |
2008 |
xx |
-6 |
1959 |
xx |
9 |
1969 |
Xx |
3 |
1979 |
Xx |
-2 |
1989 |
xx |
-4 |
1999 |
xx |
-5 |
2009 |
xx |
-2 |
1960 |
xx |
15 |
1970 |
Xx |
1 |
1980 |
Xx |
1 |
1990 |
xx |
-4 |
2000 |
xx |
-7 |
2010 |
xx |
2 |
1961 |
xx |
-6 |
1971 |
Xx |
-4 |
1981 |
Xx |
5 |
1991 |
xx |
-1 |
2001 |
xx |
6 |
2011 |
xx |
-11 |
1962 |
xx |
-5 |
1972 |
Xx |
-7 |
1982 |
Xx |
-11 |
1992 |
xx |
-2 |
2002 |
xx |
11 |
2012 |
xx |
3 |
1963 |
xx |
-2 |
1973 |
Xx |
6 |
1983 |
xx |
1 |
1993 |
xx |
-6 |
2003 |
xx |
8 |
2013 |
xx |
7 |
1964 |
xx |
0 |
1974 |
Xx |
-6 |
1984 |
Xx |
-2 |
1994 |
xx |
-5 |
2004 |
xx |
-1 |
2014 |
xx |
17 |
1965 |
xx |
-13 |
1975 |
Xx |
-2 |
1985 |
Xx |
-4 |
1995 |
xx |
6 |
2005 |
xx |
0 |
2015 |
xx |
11 |
Weights are high +ve (>+0.10) for 2015, 2014,2002,1998,1960,1958
Weights are high -ve (< - 0.10) for 2011,1982,1967,1965
Ens ave Nino34 anomaly forecasts, for leads -3, -2, -1, 0 etc: in plain numbers (ensemble mean of 12):
0.04 |
-0.04 |
-0.15 |
-0.24 |
-0.2 |
-0.23 |
-0.2 |
-0.16 |
-0.08 |
-0.01 |
0.03 |
0 |
-0.05 |
-0.09 |
0.04 |
0.18 |
0.29 |
0.28 |
0.24 |
0.18 |
0.12 |
MJJ16 |
JAS |
SON |
NDJ |
JFM17 |
MAM |
MJJ |
JAS |
SON |
NDJ |
JFM18 |
One month ago:
0.51 |
0.39 |
0.1 |
-0.2 |
-0.21 |
-0.16 |
-0.19 |
-0.19 |
-0.17 |
-0.12 |
-0.03 |
0 |
-0.01 |
-0.01 |
0 |
0.16 |
0.32 |
0.41 |
0.38 |
0.35 |
0.3 |
MJJ16 |
JAS |
SON |
NDJ |
JFM17 |
MAM |
MJJ |
JAS |
SON17 |
NDJ |
Two months ago
1.11 |
0.94 |
0.49 |
-0.18 |
-0.34 |
-0.39 |
-0.38 |
-0.42 |
-0.43 |
-0.38 |
-0.3 |
-0.17 |
-0.08 |
-0.07 |
-0.06 |
-0.07 |
0.04 |
0.15 |
0.19 |
0.13 |
0.14 |
MAM16 |
MJJ |
JAS |
SON16 |
NDJ |
JFM17 |
MAM |
MJJ |
JAS17 |
SON |
NDJ |
Three months ago:
1.67 |
1.49 |
0.97 |
0.21 |
-0.18 |
-0.37 |
-0.47 |
-0.51 |
-0.58 |
-0.58 |
-0.51 |
-0.41 |
-0.29 |
-0.27 |
-0.19 |
-0.17 |
-0.19 |
-0.11 |
-0.07 |
-0.06 |
-0.12 |
MAM16 |
MJJ |
JAS |
SON16 |
NDJ |
JFM17 |
MAM |
MJJ |
JAS |
SON |
Four months ago:
2.32 |
2.08 |
1.53 |
0.61 |
0.19 |
-0.21 |
-0.42 |
-0.59 |
-0.7 |
-0.81 |
-0.84 |
-0.78 |
-0.64 |
-0.59 |
-0.36 |
-0.22 |
-0.21 |
-0.25 |
-0.2 |
-0.18 |
-0.17 |
JFM16 |
MAM |
MJJ |
JAS |
SON16 |
NDJ |
JFM17 |
MAM |
MJJ |
JAS |
SON |
Anomalies relative to 1981-2010 climo.