THE USE OF STRICTLY DEFINED TERMS IN SUMMERTIME FORECASTS

Abstract

The desirability of using a fixed set of strictly defined terms to describe the areal distribution of summertime showers and thunderstorms in the daily State forecast is discussed, and the feasibility of doing so is investigated. The areal distribution of afternoon and evening showers in Colorado and the variations of the distributions among various sections of the State are determined. The relative frequency of occurrence of forecast categories is determined for two sets of arbitrarily defined forecast terms. Significant differences are found, on the average, in the number of showers when various forecasting terms are used to describe their occurrence. A simple objective aid for forecasting the areal distribution of showers over the entire State of Colorado is presented to illustrate that there are meteorological variables that are related to the number of showers expected over an area which could form the basis for forecasts stated in strictly defined terms.