Accession Number : AD0422398

Title :   AN INVESTIGATION OF PRE-FRONTAL PRECIPITATION ZONES,

Corporate Author : WEATHER FORECASTING RESEARCH CENTER UNIV OF CHICAGO ILL

Personal Author(s) : Omoto,Yukio

Report Date : SEP 1963

Pagination or Media Count : 84

Abstract : The synoptic aspects of the development of organized precipitation systems are considered that develop in advance of fronts in extra-tropical cyclones. Such developments are frequent in the US to the east of the Rocky Mountains, and this investigation is limited to that area. Since a number of studies were made of squall lines that occur in advance of cold fronts, the emphasis is on pre-frontal precipitation zones in which convective activity plays no important part. Two non-convective winter cases are described in great detail and compared with analyses of earlysummer cases in which convective systems were predominant. The vertical distributions of vertical motion, horizontal moisture convergence, and rate of condensation are evaluated for the non-convective cases. Detailed analyses of cloud structures are presented and a model structure of pre-frontal precipitation systems is proposed. A comparison of the convective and non-convective cases is made in regard to large-scale synoptic situations, and a number of similarities and dissimilarities are described. (Author)

Descriptors :   (*AIR MASS ANALYSIS, ATMOSPHERIC PRECIPITATION), (*ATMOSPHERIC PRECIPITATION, AIR MASS ANALYSIS), METEOROLOGICAL CHARTS, CONVECTION, TROPICAL CYCLONES, MOISTURE, TEMPERATURE INVERSION, WIND, ATMOSPHERIC MOTION, RAINFALL, WEATHER FORECASTING

Distribution Statement : APPROVED FOR PUBLIC RELEASE