146 Antonio Navarra
c;E
NINO-3 SST anomaly p lume
ECMWF forecasts trom dates in ..lan 2000
2000
Sop 1999
1 0 t - - - - - - - - = - - - - - - - - - - - r - - - - f
2000
Fig. 8.6 Forecasts "plumes" obtained from the ensembles created by the ECMWF seasonal
forecasting system. The picture shows ensembles of forecasts of NIN03 SST (thin lines)
generated around different initial condition corresponding to the nominal period indicates in
the pictures. The thick dashed line indicate the evolution of the real SST. It is possible to see
how certain initial condition give rise to a larger spread in the separation between the
different members in the forecasts. (Picture has been redrafted from images obtained from
the ECMWF)