Summary of Forecasts

For ENSO and Other SST

Dynamic Models: While a consensus among the dynamic models calls for relatively cold conditions for the tropical Pacific over the next 2-3 seasons, there are some notable differences among the models. For example, three of the models (COLA coupled, COLA anomaly coupled and SIO) predict peak cold conditions for MAM 2000, whereas the NCEP and SNU models predict peak cold conditions for DJF 1999-2000 and a more rapid return to normal during the boreal spring and summer. The BMRC and LDEO1 models predict near normal temperatures for DJF 1999-2000 and a cooling trend through late fall 2000. The LDEO3 forecast persists the current modest cold temperatures through late 2000.

Statistical Models: Similar to the dynamic models, the statistical model consensus calls for cold conditions in the tropical eastern Pacific to persist over the next 1-2 seasons. Also similar to the dynamic models there are notable differences among the forecasts. The neural network and linear inverse forecasts indicate that the peak cold anomalies will occur during DJF 2000, but cold conditions will prevail through late fall 2000. The CLIPPER, canonical correlation analysis and Markov models predict a more rapid return to normal, and the singular spectrum analysis - maximum entropy method model predicts near normal conditions for DJF 1999-2000 with slightly warm conditions throughout the remainder of 2000.

For Land Surface Temperature and Precipitation

Dynamic Models: Using both persisted and forecasted SSTA and a large ensemble of AGCM runs, the CPTEC forecast calls for relatively wet conditions to prevail in northeast Brazil for DJF 1999-2000 and MAM 2000.

Statistical Models: The multiple linear regression forecast for JFM 2000 temperatures is for relatively warm conditions in the southeast US, northeast US and southwest US and for relatively cold temperatures in the Pacific northwest US. The JFM 2000 precipitation linear regression forecast calls for relatively wet conditions in the southeast US and the Pacific northwest US. The probability of enhanced flooding is forecast to be relative high for the Pacific northwest US and streamflow is forecast to be relatively low the southwest. The probability of enhanced flooding is also forecast to be relatively high the Ohio valley and the mid-Atlantic states. The canonical correlation analysis forecast for JFM 2000 calls for cold conditions over most of Canada and relatively wet conditions over southwestern Canada. The multiple regression and discriminant analysis forecasts call for very wet conditions for northeast Brazil, but with relatively low confidence. The DJF 1999-2000 rainfall over eastern South Africa is forecasted to be slightly above normal using both multiple regression and neural network models. Canonical correlation analysis forecasts for JFM 2000 over South Africa indicate below normal maximum temperatures for most of the country. Tropical cyclone activity during November 1999 - May 2000 in the Australian region is forecast to be above average.