HIGHLIGHT:  The seasonal mean NINO3.4 anomaly was 2.8 C for OND2015, still a bit up from SON (2.4).  An anomaly of 2.8 or 2.4 would be a record, but the official determination will depend on the SST data set being used by CPC. There is some sensitivity to the particular data sets used that comes to the fore when records are broken (or not).

The CA method, acting on global OND2015 seasonal means as latest input, but using a string of global SST going back one year, has all of its members, staying >1.0 for Nino34 from now thru MAM2016.  There is a significant cool down predicted in 2016, ensemble mean -1.3 by fall 2016.

Weights were stable from last month. There are 6 (8) large +ve (-ve) weights in excess of abs(0.10).  Of the historically strong warm event years (57, 72, 82, 97)  the weights are 0.10, 0.07, 0.10 and 0.19 respectively. Only the weight for 1997 was high previously, but the other warm events have nudged up. The weight for 2014, a marginally failed warm event, continues to be high.  

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 NDJ2014 thru OND2015). Years in the table are labeled by the year of the middle month of the most recent predictor season. Weights for 1956 and 2014 are less (by 50%) because only half the members use these years ("early" members use 1956, "late" members 2014). Data currently thru Dec 2015.  

Year

IP

Wgt

Year

IP

Wgt

Year

IP

Wgt

Year

IP

Wgt

Year

IP

Wgt

Year

IP

Weigt

1956

xx

-5

1966

Xx

-11

1976

Xx

3

1986

xx

2

1996

xx

-6

2006

xx

4

1957

xx

10

1967

Xx

6

1977

Xx

4

1987

xx

4

1997

xx

19

2007

xx

-4

1958

xx

8

1968

Xx

2

1978

Xx

-3

1988

xx

-10

1998

xx

-2

2008

xx

-2

1959

xx

17

1969

Xx

-2

1979

Xx

-1

1989

xx

-1

1999

xx

-11

2009

xx

9

1960

xx

-3

1970

Xx

-1

1980

Xx

-8

1990

xx

1

2000

xx

-7

2010

xx

4

1961

xx

-3

1971

Xx

-10

1981

Xx

-9

1991

xx

0

2001

xx

1

2011

xx

9

1962

xx

-1

1972

Xx

7

1982

Xx

10

1992

xx

0

2002

xx

4

2012

xx

4

1963

xx

9

1973

Xx

-10

1983

xx

1

1993

xx

-10

2003

xx

6

2013

xx

10

1964

xx

-17

1974

Xx

-2

1984

Xx

-10

1994

xx

7

2004

xx

5

2014

xx

17

1965

xx

-6

1975

Xx

-4

1985

Xx

1

1995

xx

-1

2005

xx

-3

2015

xx

NA

 

Weights are high +ve (>+0.10) for  2014, 2013,1997, 1982,1959,1957

Weights are high -ve (< - 0.10) for 1999,1993,1988,1984,1973,1971,1966,1964

 

Ens ave Nino34 anomaly forecasts, for leads -3, -2, -1, 0 etc: in plain numbers (ensemble mean of 12):

2.79

2.78

2.61

2.04

1.45

0.95

0.46

0.09

-0.27

-0.44

-0.61

-0.7

-0.84

-1.36

-1.29

-1.05

-0.7

-0.39

-0.21

-0.11

-0.06

NDJ

JFM16

MAM

MJJ

JAS

SON16

NDJ

JFM17

MAM

MJJ

One month ago:

2.44

2.52

2.68

2.54

2.06

1.48

1

0.5

0.13

-0.2

-0.29

-0.38

-0.43

-1

-1.08

-1.03

-0.85

-0.58

-0.33

-0.22

-0.17

SON15

NDJ

JFM16

MAM

MJJ

JAS

SON

NDJ16

JFM17

MAM

MJJ

Two months ago:

2.2

2.26

2.6

2.96

2.73

2.27

1.66

1.12

0.56

0.13

-0.26

-0.37

-0.46

-0.86

-1

-1.09

-1.03

-0.87

-0.61

-0.39

-0.31

SON15

NDJ

JFM16

MAM

MJJ

JAS

SON

NDJ

JFM

MAM

Three months ago

1.89

1.89

2.14

2.7

2.91

2.76

2.35

1.77

1.23

0.65

0.16

-0.27

-0.41

-0.78

-0.82

-0.89

-0.93

-0.86

-0.72

-0.49

-0.3

JAS

SON15

NDJ

JFM16

MAM

MJJ

JAS16

SON

NDJ

JFM17

MAM

Four months ago:

1.65

1.62

1.77

2.25

2.7

2.91

2.77

2.36

1.79

1.26

0.7

0.24

-0.15

-0.58

-0.67

-0.69

-0.74

-0.76

-0.69

-0.59

-0.39

JAS

SON

NDJ

JFM2016

MAM

MJJ

JAS

SON

NDJ

JFM2017

Anomalies relative to 1981-2010 climo.