AN EXPERIMENT IN FORECASTING THE DISPLACEMENT OF 500-MILLIBAR TROUGHS AND RIDGES

Abstract

A number of simple objective methods of computing the motion of troughs and ridges at the 500-mb level were tested for a fifty-day period, with use of data over and near North America. The most useful methods, which are shown to be significantly better than extrapolation, are Petterssen's jet-stream wave formula, Rossby's long-wave formula, the grid or ?box? method, and pressure-kinematic extrapolation.