A Comparison between Observed and Computed Winds with Respect to their Applicability for Vorticity Computations

The insufficiency of computed height values for computations of derivatives such as vorticity and convergence, at least for the 300-mb and higher levels, is illustrated by theoretical and practical examples, and it is recommended to make more extensive use of observed winds. This gives a possibility to take into account the cyclostrophic and other non-geostrophic wind components for the vorticity computation which is the first step in the numerical forecasting methods (CHARNEY 1951).