MESO-SCALE STUDIES OF INSTABILITY PATTERNS AND WINDS IN THE TROPICS
Abstract
A concentrated case study of winds and precipitation echo movement in southern Florida is presented. The synoptic situation for the case and the winds aloft charts are discussed. Echo tracking equipment and procedures are described. Comparisons based upon streamline and isotach analyses are made between mean echo motion and upper air winds at grid points rather than by direct comparisons. Of the trackable echoes that existed at least 5 minutes, 72% could be tracked for 10 minutes, whereas only 36% could be tracked for 15 minutes and only 8% could be tracked for 30 minutes. Streamline analyses indicate high speed waves of short wavelength moving through the echo patterns. Wave speeds of 50 to 100 knots were indicated and in one case a 300-knot wave speed was noted. Regions of echo masses and areas of no echoes shed some doubt on the speed of these waves, however, small period variations in echo motion near a given point appear to confirm the existence of high speed waves. The convergent and divergent portions of these waves may supply a triggering action for growth and decay of clouds as they pass through an area. For comparison of echo motion with winds aloft, 50, 60, and 100-n. mi grids were used to space mean both echo motion and upper wind charts. Results indicate that in southern Florida, mean radar echo motion compares most favorably with the low level winds, in particular, the mean 5000-ft wind. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 31, 1962
- Accession Number
- AD0289808
Entities
People
- Harold P. Gerrish
- Homer W. Hiser
Organizations
- Rosenstiel School of Marine, Atmospheric, and Earth Science