MEAN-LAYER WIND CHARTS IN TROPICAL ANALYSIS

Abstract

A discussion of the usefulness of mean-lager winds?defined in terms of the net horizontal displacement of the balloon during the time interval that it ascends through specified layers?in tropical analysis and forecasting is presented. Selected wind soundings in the trade wind regime are used to illustrate the greater representativeness and reliability of the mean winds. Some evidence is presented to support the contention that the wind report in the center of a layer cannot always be trusted to give a reliable picture of the layer as a whole. Other arguments are presented in support of the mean-layer winds for analysis and forecasting purposes, and for computations of derived properties of the field of motion. Some remarks on the analysis of these charts, based on the experience obtained at the National Hurricane Research Project, are included.