Alexander, G.D., and G.S. Young, 1990

The use of quantitative surface cyclone characteristics to determine systematic departures from mean nested grid model forecast errors

National Weather Digest, 15, 6-12

Abstract

An analysis of forecast errors for surface cyclones in the Nested Grid Model (NGM) has been completed for a sample of 500 cases. In general, the NGM is more likely to forecast a cyclone too deep, too far west, and too far north. The positive correlations between 48-, 36-, and 24-h forecast errors confirm that the NGM's forecast errors depend strongly on a cyclone's characteristics. Therefore, the expected systematic exceptions to the general errors are revealed by categorizing the cyclones according to readily determinahle quantitative characteristics. These characteristics include a cyclone's position relative to the 500-mb height contour longwave pattern, its geographic location, and its forecast intensity. A review of previous studies suggests possible origins for some of the forecast errors.