Results of Forecasting with the Barotropic Model on an Electronic Computer (BESK)

A series of twenty-four 24-hour forecasts have been completed using the barotropic model of the atmosphere. The results of these forecasts are better than previous tests with this model have indicated. The average correlation coefficient between computed and observed height changes of the 500 mb surface is 0.77, the error in the forecast height changes is 89 m against an average observed change of IZI m. The errors are mainly due to the following factors:

1. Erroneous assumptions at the boundary of the forecast area.
2. Inaccurate analysis of the initial data over the Atlantic.
3. Inaccuracy in forecasting components of the niotion of a scale only a few times larger than the grid size.
4. Baroclinic developments.

The computations indicate that the present results may be improved considerably by trying to eliminate errors listed under (1)–(3).