300-mb Isotach Analysis1

Abstract

A "mean-wind" technique is presented for estimating (for a constant-pressure level) the position and strength of the core of maximum winds between two rawinsonde stations located four to nine latitude degrees apart. An example of the application of the method is given, and shortcomings of the method are described. To test the method, 37 computations were made. The resulting core speeds and positions are compared with Project "Jet-Stream" flight winds and "Whooper" reconnaissance winds. The mean speed-error of the 37 computations is -3.5 kn and the RMS error is 17 kn. It is concluded that the "mean-wind" technique is operationally feasible and that its employment in conjunction with other analysis techniques now in use will contribute to analysis in the jet-stream region.FIG. 1. U. S. rawinsonde network as of 1 April 1957.