The El Niño forecasts are part of an ongoing research effort at COLA, and do not represent official forecasts. These forecasts should not be used as the basis of any commercial, policy, or other decisions. They are strictly research tools for advancing the understanding of the ocean-atmosphere system.
The NINO3 time series of the predicted
sea surface temperature anomalies (SSTA) for three
forecasts initialized on October 1, November 1 and December
1, 1996 are shown below.
Each forecast is run for 18 months.
All three forecasts indicate relatively cool conditions for October
1996 through April 1997. The NINO3 SSTA steadily increases in all
three forecasts indicating warm conditions in the eastern Pacific for
boreal fall 1997 and winter 1997-98.
| Time evolution of the NINO3 SSTA forecast. The solid red curve corresponds to the forecast initialized in October 1996, the dashed blue curve corresponds to the November 1996 forecast and the dotted green curve corresponds to the December 1996 forecast. |
The ensemble mean (average of all three forecasts) horizontal
structure of the predicted SSTA for the boreal winter of 1996-97, the
boreal spring of 1997 and the boreal summer of 1997 are shown in the
three panels below. During the boreal winter of 1996-97 the
model predicts relatively cool conditions throughout the tropical
Pacific. There is steady warming trend through the boreal spring 1997
to near normal conditions. The warming continues through the boreal
summer 1997 indicating relative warm conditions in a narrow region
along the equator.
| The ensemble mean anomalies in sea surface temperature (SSTA). The top panel shows the predicted ensemble mean averaged over December-January-February 1996-97. The middle panel shows the predicted ensemble mean SSTA averaged from March 1997 to May 1997. The bottom panel shows the ensemble mean averaged over June-July-August 1997. |
These latest three forecats should be compared to the forecast initialized in April 1996 - September 1996 (see the June and September 1996 pages on this website). The forecasts initialized in April, May, June and July 1996 were quite similar to each other and called for relatively warm conditions for the boreal winter 1996-97. The forecasts initialized in August and September 1996 shifted the peak warming considerably later during 1997 giving predictions that were somewhat more consistent with the current three forecasts. The current forecasts give peak warming during October 1997, whereas the forecast initialized in April-June 1996 gave peak warm conditions in January 1997. The April-June 1996 forecasts are consistent with several hindcast experiments with this model where there was a tendency to predict the onset of El Niño too early during the transition from cold to near normal conditions. This problem is currently being investigated in a detailed predictability study.
