Science and technology
Weather forecasting Continental divide
Europeans do not just talk about the weather more than Americans do.They are better at forecasting it as well
IT WAS far too small a victory to count as an equaliser.But cheers were still heard in American meteorological circles after the storm that hit the country's east coast last month left the city of New York mostly unscathed.
For more than two decades the Global Forecast System (GFS), the leading weather-prediction model produced in the United States, has been notably less accurate than its chief competitor, published by the European Centre for Medium-Range Weather Forecasts (ECMWF).Although this deficit went largely unnoticed for years, it was laid bare by Hurricane Sandy.A week before that storm's landfall in 2012, the ECMWF predicted it would veer towards the coast while the GFS showed it remaining at sea.
In response to this failure, America's Congress authorised 34m of extra money to spend on forecasting.A new version of the GFS went into operation on January 14th, and two weeks later it passed with flying colours.On January 25th the ECMWF predicted that New York would, on the 27th, labour under 64cm (25 inches) of snow brought by the storm pictured above.The GFS suggested 18cm. That turned out to be far closer to the truth.
It is, however, too early for the Americans to celebrate.The GFS projection for the blizzard's western edge differed from the ECMWF's by 200km (120 miles)—a weather-forecasting hairs'-breadth.The only reason anyone noticed this discrepancy was that the gap happened to encompass the country's most populous city.This episode, moreover, may have been a fluke.