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 March 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
Apr 2002 0 0% 2% 4% 39% 54%
May 2002 1 1% 1% 9% 35% 54%
Jun 2002 2 1% 7% 6% 46% 40%
Jul 2002 3 4% 12% 8% 46% 30%
Aug 2002 4 11% 21% 20% 36% 12%
Sep 2002 5 16% 18% 22% 34% 10%
Oct 2002 6 19% 20% 15% 33% 12%
Nov 2002 7 14% 12% 25% 25% 24%
Dec 2002 8 20% 44% 14% 11% 11%
Jan 2003 9 35% 34% 14% 5% 11%
Feb 2003 10 22% 21% 19% 16% 22%
Mar 2003 11 20% 17% 20% 22% 21%


NINO3
Month lead-time cold cool neutral warm hot
Apr 2002 0 2% 9% 15% 25% 49%
May 2002 1 5% 12% 18% 26% 39%
Jun 2002 2 23% 19% 19% 23% 16%
Jul 2002 3 31% 26% 17% 18% 8%
Aug 2002 4 26% 25% 20% 18% 11%
Sep 2002 5 21% 33% 15% 15% 16%
Oct 2002 6 24% 24% 23% 15% 14%
Nov 2002 7 22% 25% 19% 21% 14%
Dec 2002 8 23% 24% 19% 15% 19%
Jan 2003 9 22% 22% 23% 17% 15%
Feb 2003 10 24% 28% 17% 13% 18%
Mar 2003 11 22% 24% 16% 17% 22%


NINO3.4
Month lead-time cold cool neutral warm hot
Apr 2002 0 0% 16% 23% 28% 34%
May 2002 1 5% 14% 27% 27% 27%
Jun 2002 2 44% 25% 16% 13% 3%
Jul 2002 3 38% 29% 13% 14% 6%
Aug 2002 4 46% 19% 15% 10% 10%
Sep 2002 5 46% 21% 13% 11% 9%
Oct 2002 6 43% 19% 17% 13% 9%
Nov 2002 7 43% 21% 14% 16% 6%
Dec 2002 8 43% 21% 16% 13% 7%
Jan 2003 9 36% 25% 15% 15% 9%
Feb 2003 10 32% 25% 17% 16% 10%
Mar 2003 11 33% 21% 19% 17% 10%


NINO4
Month lead-time cold cool neutral warm hot
Apr 2002 0 0% 7% 13% 35% 45%
May 2002 1 0% 9% 15% 33% 43%
Jun 2002 2 4% 13% 28% 23% 31%
Jul 2002 3 7% 15% 19% 33% 26%
Aug 2002 4 17% 11% 22% 29% 21%
Sep 2002 5 14% 12% 24% 30% 20%
Oct 2002 6 37% 18% 16% 18% 12%
Nov 2002 7 39% 23% 17% 13% 8%
Dec 2002 8 39% 23% 18% 12% 7%
Jan 2003 9 36% 18% 25% 13% 9%
Feb 2003 10 28% 24% 17% 17% 13%
Mar 2003 11 20% 25% 18% 23% 14%