HIGHLIGHT: The seasonal mean NINO3.4 anomaly was +1.01 for FMA2009, a noticeable decrease from JFM. The warm event is winding down or has already ended.

The CA method, acting on global FMA2010 seasonal means as latest input forecasts the 3 mo running mean anomaly for Nino34 to stay in El Nino territory only thru MAM, followed by a rapid cool-off later in 2010, with ve Nino34 anomalies by MJJ, and 80% of the members decidedly in La Nina territory by JAS.

Weights have not changed dramatically from 1 month ago (which is as it should be for CA-prediction to succeed). Many years with high ve weight!. And more years than 1 month ago have high +ve weight note an exceptionally high positive weight (+0.23) for 1969.

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 MAM2009 thru FMA2010). Years in the table are labeled by the year of the middle month of the most recent predictor season. Weights for 1956 and 2009 are less (by 50%) because only half the members use these years ("early" members use 1956, "late" members 2009). Data currently thru Apr 2010.

Year

IP

Wgt

Year

IP

Wgt

Year

IP

Wgt

Year

IP

Wgt

Year

IP

Wgt

Year

IP

Weigt

1956

xx

-1

1966

xx

5

1976

xx

-2

1986

xx

-5

1996

xx

13

2006

xx

0

1957

xx

-17

1967

xx

-2

1977

xx

-1

1987

xx

3

1997

xx

-2

2007

xx

9

1958

xx

8

1968

xx

-9

1978

xx

4

1988

xx

7

1998

xx

7

2008

xx

2

1959

xx

-1

1969

xx

23

1979

xx

-3

1989

xx

-2

1999

xx

-6

2009

xx

0

1960

xx

-12

1970

xx

11

1980

xx

-5

1990

xx

10

2000

xx

-3

2010

xx

NA

1961

xx

-7

1971

xx

8

1981

xx

-2

1991

xx

5

2001

xx

0

xx

Xx

1962

xx

2

1972

xx

-4

1982

xx

-6

1992

xx

3

2002

xx

14

xx

Xx

1963

xx

-1

1973

xx

9

1983

xx

0

1993

xx

-3

2003

xx

16

xx

Xx

1964

xx

1

1974

xx

0

1984

xx

-9

1994

xx

-13

2004

xx

-1

xx

Xx

1965

xx

-16

1975

xx

1

1985

xx

-10

1995

xx

5

2005

xx

11

xx

Xx

 

Weights are high +ve (>+0.10) for 2005,2003,2002,1996,1990,1970,1969. Weights are high -ve (< - 0.10) for 1994,1985,1965,1960,1957.

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

1.01

0.81

0.36

-0.21

-0.42

-0.57

-0.71

-0.83

-1.01

-1.15

-1.15

-1.03

-0.74

-0.45

-0.23

-0.06

0.02

0.19

0.33

0.46

0.49

MAM

MJJ

JAS10

SON

NDJ

JFM11

MAM

MJJ

JAS11

SON

One month ago:

1.29

1.11

0.62

-0.07

-0.26

-0.43

-0.56

-0.69

-0.77

-0.89

-0.97

-0.94

-0.81

-0.56

-0.29

-0.11

0.04

0.1

0.27

0.41

0.53

JFM10

MAM

MJJ

JAS

SON

NDJ

JFM11

MAM

MJJ

JAS

SON11

 

Two months ago:

1.54

1.4

0.98

0.31

0.06

-0.04

-0.15

-0.28

-0.4

-0.43

-0.45

-0.47

-0.44

-0.36

-0.2

0

0.12

0.21

0.21

0.29

0.36

JFM10

MAM

MJJ

JAS

SON10

NDJ

JFM11

MAM

MJJ

JAS

Three months ago:

1.67

1.59

1.26

0.68

0.34

0.15

0.09

-0.02

-0.15

-0.26

-0.25

-0.23

-0.21

-0.22

-0.19

-0.06

0.12

0.19

0.19

0.1

0.14

NDJ

JFM10

MAM

MJJ

JAS

SON10

NDJ

JFM11

MAM

MJJ

JAS11

 

Anomalies relative to 1971-2000 climo.