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 January 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
Feb 2002 0 33% 39% 15% 11% 2%
Mar 2002 1 33% 28% 15% 21% 4%
Apr 2002 2 29% 22% 25% 20% 4%
May 2002 3 26% 25% 16% 25% 9%
Jun 2002 4 29% 24% 26% 13% 8%
Jul 2002 5 31% 22% 23% 18% 7%
Aug 2002 6 17% 26% 20% 24% 13%
Sep 2002 7 18% 25% 19% 24% 13%
Oct 2002 8 20% 27% 16% 21% 16%
Nov 2002 9 33% 25% 14% 10% 18%
Dec 2002 10 27% 32% 15% 8% 19%
Jan 2003 11 26% 17% 25% 16% 16%


NINO3
Month lead-time cold cool neutral warm hot
Feb 2002 0 5% 56% 35% 4% 0%
Mar 2002 1 25% 44% 15% 14% 2%
Apr 2002 2 29% 32% 20% 12% 7%
May 2002 3 19% 27% 22% 19% 14%
Jun 2002 4 18% 25% 22% 24% 11%
Jul 2002 5 19% 22% 18% 29% 12%
Aug 2002 6 18% 23% 21% 23% 15%
Sep 2002 7 20% 29% 19% 21% 11%
Oct 2002 8 17% 25% 23% 18% 16%
Nov 2002 9 17% 27% 22% 21% 14%
Dec 2002 10 21% 27% 21% 21% 10%
Jan 2003 11 21% 19% 26% 18% 16%


NINO3.4
Month lead-time cold cool neutral warm hot
Feb 2002 0 2% 31% 65% 2% 0%
Mar 2002 1 15% 36% 30% 18% 1%
Apr 2002 2 19% 36% 27% 12% 5%
May 2002 3 25% 30% 27% 14% 5%
Jun 2002 4 16% 27% 23% 22% 12%
Jul 2002 5 13% 27% 22% 23% 15%
Aug 2002 6 16% 27% 22% 20% 15%
Sep 2002 7 15% 29% 22% 21% 14%
Oct 2002 8 15% 25% 22% 23% 15%
Nov 2002 9 17% 26% 23% 24% 10%
Dec 2002 10 16% 24% 24% 24% 12%
Jan 2003 11 20% 20% 25% 20% 14%


NINO4
Month lead-time cold cool neutral warm hot
Feb 2002 0 6% 35% 21% 35% 3%
Mar 2002 1 8% 30% 26% 31% 5%
Apr 2002 2 17% 27% 22% 23% 10%
May 2002 3 15% 28% 25% 20% 13%
Jun 2002 4 18% 24% 23% 20% 15%
Jul 2002 5 25% 25% 20% 16% 13%
Aug 2002 6 18% 23% 21% 23% 14%
Sep 2002 7 26% 27% 20% 17% 9%
Oct 2002 8 20% 28% 24% 18% 10%
Nov 2002 9 18% 30% 24% 16% 12%
Dec 2002 10 17% 29% 24% 17% 14%
Jan 2003 11 21% 25% 28% 15% 11%