The US weather model is now the fourth best in the world

Forecast models are measured by their anomaly correlation scores, and the GFS model (black line) now ranks fourth among global models. (credit: Cliff Mass)

The forecasting supremacy of the European Center for Medium-Range Weather Forecasts and its global weather prediction model is well documented. This most glaringly reached the American public when only the European forecast model correctly predicted Hurricane Sandy would turn toward the northeastern United States in 2012, rather than remaining out to sea. For several years, the United States and its global forecasting system (GFS) have been struggling to catch up.

But as the United States' forecasting enterprise has more or less stayed the same, other nations are now equaling and passing the GFS model. Perhaps the most well accepted method of measuring a model's accuracy is by scoring its "anomaly correlation," a measure of its ability to accurately predict observations (a score of 1 is perfect). For the northern hemisphere during the last two months, as measured at the 500mb level of the atmosphere (about 5.5km above the Earth's surface), the European model scores by far the highest, at .905. It is followed by the United Kingdom's model (.870), Canadian model, (.868) and finally the GFS (.857).

On Tuesday, Cliff Mass, a University of Washington atmospheric scientist who closely tracks the forecast model "wars," wrote about the GFS model's poor performance relative to other nations. He concluded: "It is not that U.S. global (numerical weather prediction) is getting less skillful, but that other nations are innovating and pushing ahead faster. This situation could be greatly improved within a year, but to do so will require leadership, innovation, and a willingness to partner with others in new ways."

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Source: Scientific Method – Ars Technica http://ift.tt/28Nbc0T