Statistical Probabilistic ENSO Forecasts

Probabilistic Forecasts of ENSO Indices Using Statistical Models

Simon J. Mason

Scripps Institution of Oceanography

The forecasts below were produced using February 2002 observed sea-surface temperatures, and with version 3.04 of the SPEF (Statistical Probabilistic ENSO Forecasts) model. Previous forecasts are available online.

NINO1&2
Month lead-time cold cool neutral warm hot
Mar 2002 0 5% 10% 28% 40% 17%
Apr 2002 1 14% 41% 17% 26% 3%
May 2002 2 21% 26% 29% 18% 7%
Jun 2002 3 31% 29% 26% 10% 3%
Jul 2002 4 46% 24% 15% 11% 4%
Aug 2002 5 45% 32% 12% 7% 4%
Sep 2002 6 52% 30% 8% 7% 3%
Oct 2002 7 52% 25% 12% 7% 4%
Nov 2002 8 50% 23% 8% 11% 7%
Dec 2002 9 48% 30% 10% 6% 6%
Jan 2003 10 39% 34% 17% 3% 7%
Feb 2003 11 31% 11% 16% 19% 23%


NINO3
Month lead-time cold cool neutral warm hot
Mar 2002 0 2% 11% 34% 36% 16%
Apr 2002 1 9% 17% 22% 30% 21%
May 2002 2 9% 15% 21% 28% 27%
Jun 2002 3 14% 19% 15% 19% 33%
Jul 2002 4 15% 19% 16% 19% 32%
Aug 2002 5 15% 17% 17% 21% 31%
Sep 2002 6 14% 21% 15% 22% 29%
Oct 2002 7 15% 16% 17% 27% 26%
Nov 2002 8 14% 17% 15% 24% 30%
Dec 2002 9 15% 18% 15% 22% 30%
Jan 2003 10 14% 15% 20% 21% 31%
Feb 2003 11 14% 21% 17% 21% 27%


NINO3.4
Month lead-time cold cool neutral warm hot
Mar 2002 0 0% 9% 34% 48% 8%
Apr 2002 1 1% 17% 28% 30% 24%
May 2002 2 14% 16% 23% 29% 19%
Jun 2002 3 14% 20% 16% 23% 28%
Jul 2002 4 14% 19% 17% 19% 31%
Aug 2002 5 14% 19% 16% 23% 28%
Sep 2002 6 15% 19% 17% 21% 27%
Oct 2002 7 9% 23% 20% 23% 25%
Nov 2002 8 10% 23% 17% 21% 29%
Dec 2002 9 13% 20% 18% 21% 28%
Jan 2003 10 14% 17% 23% 17% 29%
Feb 2003 11 15% 17% 25% 14% 29%


NINO4
Month lead-time cold cool neutral warm hot
Mar 2002 0 0% 2% 23% 58% 17%
Apr 2002 1 1% 12% 20% 42% 25%
May 2002 2 1% 19% 17% 35% 29%
Jun 2002 3 7% 17% 22% 25% 29%
Jul 2002 4 12% 14% 18% 28% 29%
Aug 2002 5 14% 22% 15% 21% 28%
Sep 2002 6 13% 20% 16% 18% 32%
Oct 2002 7 10% 22% 15% 25% 29%
Nov 2002 8 9% 24% 19% 23% 25%
Dec 2002 9 9% 24% 16% 23% 28%
Jan 2003 10 12% 18% 27% 17% 27%
Feb 2003 11 8% 22% 21% 19% 30%