The Long View of Weather

Abstract

Eighteen countries have participated in a decade-long project, The Tropical Ocean Global Atmosphere study, aimed at understanding how the Pacific waters and atmosphere conspire to bring about El Ninos and La Ninas. As part of the study, computer models for predicting when the tropical Pacific will swing toward warm or cool temperatures have been developed. Although this year a subtle el Nino was difficult to anticipate, major warmings and coolings advertise themselves and the models have started to show skill at detecting such events 12-18 months in advance. This article discusses the ramifications of such investigative modeling on other predictions - for example, how weather patterns will be disrupted in the US by El Nino and other 3-6 month weather predictions. General Circulation Models are being used as a basis for these investigations, marking a major shift in meteorlogical philosophy from concentrating on weather statistics, analogies with previous situations, and judgments.