Accession Number : AD0720872

Title :   Studies of Storms by Doppler Radar.

Descriptive Note : Final rept. 16 Feb 70-15 Mar 71,

Corporate Author : ALLIED RESEARCH ASSOCIATES INC CONCORD MASS

Personal Author(s) : Wexler,Raymond

Report Date : 26 MAR 1971

Pagination or Media Count : 44

Abstract : Wind field and convergence were determined by Doppler radar in a 14-hour storm, 10-11 Feb. 1970, characterized by continuous rain and heavy shower activity. The wind field was quite variable at all levels. Some of the variability may have been due to vertical motions in the vicinity of heavy showers. Intermittent discontinuities in the wind field below 1.5 km during a three-hour period are interpreted to be due to the descent of high velocity air from upper levels in downdrafts generated by intense shower activity. The convergence field was characterized by general convergence at low levels and divergence at upper levels during most of the storm. In the storm of 2 April 1970, a southwesterly jet of 38 to 45 m/sec prevailed at 2 to 6 km. Lower velocities from above penetrated to the 5 or 6 km level for a period of about two hours. During this period there were discontinuities in the wind field over a 15-minute period which occurred first at 6 to 6.6 km and then 12 minutes later at 4.9 to 6 km. These discontinuities coincided with sharp increases in reflectivity on the edge of heavy showers. These discontinuities are interpreted to be the result of the interaction of the environmental wind with the cumuliform towers characterized by strong updrafts and heavy shower activity. (Author)

Descriptors :   (*STORMS, *DOPPLER RADAR), RAINFALL, WIND, CONVECTION(ATMOSPHERIC), REFLECTIVITY, THUNDERSTORMS, INTENSITY, RADIOSONDES, RADAR TRACKING, TABLES(DATA)

Subject Categories : Meteorology
      Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE