Global Forecast System. The operational numerical weather forecasting model run by NCEP. The GFS superceded the AVN and MRF models, on which it is largely based. Forecast data from the GFS is available out to 180 hours at full resolution and 16 days at a reduced resolution.
10:05 EDT Visitors to the Grand Canyon in the United States have been treated to a spectacular sight of clouds filling the massive prehistoric gorge.