Hurricane Joaquin Forecast: Why U.S. Weather Model Has Fallen Behind
By early 2013, the European model had nearly 10 times the raw computing capacity of the Global Forecast System, or G.F.S., which is run by theNational Weather Service. There were other problems, too, and the cumulative effect was obvious and irrefutable: The G.F.S. was doing worse than it rivals, and it played out in high-profile cases, like Sandy.
.. The European model’s data assimilation relies on more observations than the G.F.S. — including satellite measurements of radiation from clouds, which is crucial in areas with relatively few land observations. It also assimilates the data over time, allowing the model to start with the evolution of the weather heading into the forecast period, not just a snapshot.