Many weather forecast guidance systems are used to formulate global forecasts. Over 150 numerical forecast models are used each day, both external and internal datasets. These models include government models such as the European Centre ECMWF and the U.S. Global Forecast System (GFS). Also, AccuWeather incorporates proprietary high-resolution models that downscale forecasts to specific locations and strategic regional domains to predict weather with further accuracy. AccuWeather’s unique blending and weighting algorithms have been developed over the last several decades. These algorithms optimally apply the many forecast inputs to provide highly accurate forecasts.