Dynamic Models: For the tropical Pacific, the dynamic forecasts agree that there will be at least moderate La Niña conditions in the next 1-2 seasons. There is some disagreement among the models as to the strength and timing of the cooling in the eastern Pacific. The NCEP model forecasts a relatively weak La Niña for the boreal winter of 1998-99, whereas both COLA forecasts call for considerably stronger La Niña conditions. The COLA anomaly coupled model predicts relatively large cold SSTA in the central Pacific. The NCEP and COLA models return to near normal conditions in the summer and fall of 1999. Similarly, the SIO/MPI model predicts relatively large cold SSTA in the central Pacific with relatively weak anomalies along the east coast of South America and a fairly rapid return to near normal in the summer and fall of 1999. The UCLA model is calling for somewhat more moderate La Niña conditions. Both versions of the LDEO model predict modest La Niña conditions that persist throughout 1999 and return to normal by early 2000. The BMRC model calls for a strong cooling trend in the next 2-3 months with weaker cooling continuing until September 1999. The BMRC forecast returns to normal by early 2000.

Statistical Models: The linear Inverse model predicts moderate La Niña conditions for the winter of 1998-99 decaying rapidly though the summer of 1999. The neural network model prediction also calls for modest La Niña conditions to peak around the first two months of 1999. The constructed analogue prediction is for relatively strong La Niña conditions peaking in late 1998. The CLIPPER and the NCEP Markov model forecasts also call for a moderate to strong cold event for late 1998. The singular spectrum analysis-maximum entropy method forecasts very weak La Niña or near normal conditions for the winter of 1998-99. The linear inverse model predicts an end to the warm conditions in the Caribbean and the north tropical Atlantic in early 1999.

Dynamic Models: The NCEP tier two AGCM forecast for North American temperatures is calling for relatively warm conditions throughout much of North America through early boreal winter 1998-99. The precipitation forecast calls for relatively dry conditions in much of the eastern and southern parts of the U.S. to prevail through early 1999. In the northwest U.S. and extreme southwestern Canada relatively wet conditions are forecasted through early 1999. ECPC seasonal forecast using persisted SSTA and NCEP's regional spectral model indicate windy and dry conditions for the southern U.S. and northern Mexico though October 1998. Above normal rainfall is forecasted for the Gulf of Mexico, the Caribbean and the eastern tropical Pacific. The UKMO AGCM rainfall forecast in central east Africa for October -December 1998 using persisted SSTA calls for below average rainfall in the south of the region (southwest Uganda, south Kenyan, Rwanda, Burundi, east Democratic Republic of Congo, Tazania, east Zambia, Malawi, north Mozambique and Zimbabwe)and near normal rainfall in the north (southern Sudan and Ethiopia, northern Kenya and Uganda and northeastern Democratic Republic of Congo).

Statistical Models: Linear regression temperature forecasts for the U.S. during October-December 1998 indicate relatively warm conditions will prevail in the far west and southeast. Above normal temperatures are expected for Kansas and Nebraska, and below normal temperatures for south central Texas. The October-December 1998 linear regression precipitation forecast calls for dry conditions in the far southwest U.S. and the southern tip of Florida, whereas in central Florida wet conditions are forecasted. The CCA forecast for Canada during December-February 1998-99 calls for relatively cold temperatures in the east and warm temperatures in the west, particularly to the north. The CCA Canada precipitation forecast for October-December 1998-99 calls for dry conditions in south central and northeast Canada and wet conditions in the central part of the country. The CCA forecast for the Pacific islands indicate that, except for Hawaii, the U.S. affiliated stations will have above normal rainfall this boreal fall and winter. The CCA east African October-December 1998 rainfall forecast calls for slightly below normal precipitation along the coast of Tanzania, Somalia and across Kenya and Sudan. The empirical forecast for Uruguay calls for a dryer than normal October-December 1998 period. Empirical hurricane forecasts indicate a below normal season.