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Seasonal Weather Prediction & Regional Climate modeling

Some of the most dramatic progress in forecasting has taken place on the scale known as seasonal to interannual. It's impossible to foresee how day-to-day weather will take shape in that time frame. But forecasters can now make useful conclusions up to a year or more in advance about the likelihood of warmer, colder, wetter, or drier conditions than average.

Adjusting research radar on a buoy. Much of the success in seasonal-to-interannual forecasting stems from research at NCAR and elsewhere, especially on the roles that El Niño and La Niña play in global climate. As recently as 1982, there was no observing or forecasting system designed specifically to capture these warmings and coolings in the tropical Pacific Ocean. Improved data from sensors mounted on buoys has enabled meteorologists to monitor the Pacific on a daily basis for signs of a developing El Niño or La Niña. Computer models are becoming increasingly skilled at projecting the evolution of these events.

NCAR scientists have also turned their attention to other ocean-atmosphere interactions that affect global climate for months at a time. One recent study explored a potential connection between sea-surface temperatures in the eastern tropical Atlantic and the development of El Niño in the Pacific. The tropical Atlantic may also play a role in the North Atlantic Oscillation, a highly variable pattern that affects wintertime temperatures and rainfall across the northeast United States, eastern Canada, and Europe. Yet another oscillation, this one affecting the spread of Arctic cold, may explain why many winters since 1980 have been unusually mild across much of the Northern Hemisphere.

To study these and other climate cycles, NCAR uses long-range computer models and sophisticated statistical analyses.