A brief description is given of the preparation of charts depicting vorticity and space-mean flow patterns, in a manner similar to that proposed by Fjørtoft (1952). A comparison of the velocity of pronounced vorticity centers and the velocity of the wind over the centers indicated by the space-mean flow pattern is made from a series of daily charts for the autumn and early winter of 1953. It is found that the directions of motion of the centers and of the winds do not differ by more than ten degrees in slightly more than half the cases. A correlation coefficient of +0.69 is found between the speed of the centers and the speed of the winds. Use of the space-mean wind as a method of forecasting the displacement of the vorticity centers appears to be superior to the use of extrapolation. Application of the Rossby wave formula to all ridges and troughs in the space-mean flow patterns yields forecasts of the displacement of these features which are slightly better than extrapolation forecasts.

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