An Analysis of Numerical Cloud Forecasts. A Statistical Analysis of Total Cloud Cover Forecasts Produced by Two Air Weather Service Numerical Programs

摘要

The Air Weather Service, USAF, has a requirement to provide total cloud cover forecasts for the northern hemisphere. Three approaches were made to provide numerical forecasting programs to meet this requirement: (1) A 'Dynamic Cloud Forecasting Model' based upon forecasting the trajectories of air parcels; (2) A '4-layer Cloud Forecasting Model' based upon the forecasting of adiabatic vertical velocities and a statistical correlation between cloud cover and the forecast dewpoint depression; and (3) a 'Multiple-discriminant Analysis' program developed by applying statistical techniques to determine a minimum number of predictors which would most efficiently forecast total cloud cover by statistical methods.