ABSTRACT

In the last few decades, advances in high-performance computing and a better understanding of oceanic and atmospheric processes have allowed forecasters to make more accurate short- and long-term weather predictions. By tracking jet-stream oscillations and quickly changing phenomena such as the North Atlantic Oscillation and the Pacific/North America pattern, short-term forecast models provide reasonable day-to-day accuracy out to approximately two weeks. Long-term forecast models may provide some accuracy several months in advance in certain situations, such as the presence of El Niño or La Niña during the cold season. Effects of annual (e.g. El Niño/Southern Oscillation) to decadal (e.g. Pacific Decadal Oscillation) variations are better understood than the processes that cause them.