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 November 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
Dec 2002 0 0% 0% 2% 33% 65%
Jan 2003 1 2% 4% 11% 29% 54%
Feb 2003 2 14% 3% 21% 23% 39%
Mar 2003 3 14% 17% 28% 17% 23%
Apr 2003 4 21% 22% 18% 21% 18%
May 2003 5 23% 26% 23% 11% 17%
Jun 2003 6 34% 26% 22% 6% 13%
Jul 2003 7 49% 19% 13% 7% 12%
Aug 2003 8 19% 31% 27% 8% 14%
Sep 2003 9 40% 34% 5% 11% 10%
Oct 2003 10 48% 11% 21% 6% 13%
Nov 2003 11 53% 15% 11% 6% 15%


NINO3
Month lead-time cold cool neutral warm hot
Dec 2002 0 0% 0% 0% 25% 75%
Jan 2003 1 0% 0% 1% 28% 70%
Feb 2003 2 1% 1% 5% 23% 70%
Mar 2003 3 1% 5% 10% 31% 53%
Apr 2003 4 12% 11% 21% 22% 34%
May 2003 5 24% 25% 32% 6% 13%
Jun 2003 6 25% 28% 25% 12% 11%
Jul 2003 7 23% 24% 23% 14% 15%
Aug 2003 8 38% 16% 26% 9% 11%
Sep 2003 9 39% 18% 24% 9% 9%
Oct 2003 10 39% 13% 30% 6% 13%
Nov 2003 11 38% 22% 23% 8% 9%


NINO3.4
Month lead-time cold cool neutral warm hot
Dec 2002 0 0% 0% 0% 25% 75%
Jan 2003 1 0% 0% 6% 34% 60%
Feb 2003 2 0% 0% 4% 27% 69%
Mar 2003 3 0% 5% 14% 25% 56%
Apr 2003 4 10% 15% 20% 27% 27%
May 2003 5 13% 11% 21% 21% 34%
Jun 2003 6 30% 29% 16% 12% 14%
Jul 2003 7 33% 16% 20% 18% 13%
Aug 2003 8 38% 24% 15% 11% 11%
Sep 2003 9 33% 23% 24% 7% 13%
Oct 2003 10 38% 26% 18% 7% 11%
Nov 2003 11 44% 22% 13% 11% 11%


NINO4
Month lead-time cold cool neutral warm hot
Dec 2002 0 0% 0% 1% 21% 78%
Jan 2003 1 0% 2% 19% 16% 63%
Feb 2003 2 1% 3% 37% 35% 23%
Mar 2003 3 2% 8% 21% 31% 38%
Apr 2003 4 1% 12% 12% 33% 43%
May 2003 5 3% 25% 27% 17% 28%
Jun 2003 6 11% 14% 26% 22% 27%
Jul 2003 7 24% 28% 18% 15% 15%
Aug 2003 8 26% 41% 8% 15% 10%
Sep 2003 9 25% 39% 14% 13% 8%
Oct 2003 10 33% 25% 26% 5% 12%
Nov 2003 11 36% 28% 17% 6% 12%