HIGHLIGHT:  The seasonal mean NINO3.4 anomaly was about -0.21 C for MAM2013, little change from FMA2013 (-0.12). 

The CA method, acting on global MAM2013 seasonal means as latest input, but using a string of global SST going back one year, has 10 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! Two members have a different opinion and grow >+0.5 late in 2013.

Weights have changed little from last month for most years except a few big weights that went down. 1987 (thru December that particular past situation was labeled 1986) has now been holding on to a large negative weight for a whole year: since spring 2012.

OCN flavor is visible. The last 13 years have a +ve weight except for 2 years. 1986-1999 is solidly negative except for 2 years..

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 AMJ2012 thru MAM2013). 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 May 2013.

Year

IP

Wgt

Year

IP

Wgt

Year

IP

Wgt

Year

IP

Wgt

Year

IP

Wgt

Year

IP

Weigt

1956

xx

 0

1966

xx

 4

1976

Xx

-4

1986

xx

-10

1996

xx

-6

2006

xx

-1

1957

xx

 4

1967

xx

-2

1977

Xx

 1

1987

xx

-15

1997

xx

-2

2007

xx

 6

1958

xx

 3

1968

xx

 2

1978

Xx

 6

1988

xx

 6

1998

xx

-4

2008

xx

10

1959

xx

 0

1969

xx

-7

1979

Xx

 7

1989

xx

-3

1999

xx

-3

2009

xx

 8

1960

xx

-2

1970

xx

 6

1980

Xx

-2

1990

xx

 7

2000

xx

 5

2010

xx

 8

1961

xx

-7

1971

xx

-3

1981

Xx

-2

1991

xx

-2

2001

xx

 4

2011

xx

 0

1962

xx

 9

1972

xx

 0

1982

Xx

-1

1992

xx

-4

2002

xx

 9

2012

xx

 9

1963

xx

 3

1973

xx

-3

1983

xx

-7

1993

xx

-5

2003

xx

 6

2013

xx

NA

1964

xx

 6

1974

xx

-13

1984

Xx

 6

1994

xx

-5

2004

xx

-5

xx

Xx

1965

xx

 1

1975

xx

-9

1985

Xx

 1

1995

xx

-3

2005

xx

 3

xx

Xx

 

Weights are high +ve (>+0.10) for 2008

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):

-0.21

-0.24

-0.24

-0.2

-0.21

-0.25

-0.26

-0.26

-0.28

-0.33

-0.32

-0.28

-0.13

0.04

0.22

0.29

0.28

0.29

0.4

0.6

0.68

MAM13

MJJ

JAS

SON

NDJ

JFM14

MAM

MJJ

JAS

SON14

NDJ

One month ago:

-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

Two months 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

Three 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

Four 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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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