Buoyancy and shear characteristics of hurricane-tornado environments

• Published in: Monthly weather review 1991-08, Vol.119 (8), p.1954-1978
• Main Author: Mccaul, Eugene W., Jr
• Format: Article
• Language: English
• Subjects: Earth, ocean, space; Exact sciences and technology; External geophysics; Meteorology; Meteorology And Climatology; Storms, hurricanes, tornadoes, thunderstorms
• ISSN: 0027-0644; 1520-0493
• DOI: 10.1175/1520-0493(1991)119<1954:bascoh>2.0.co;2

This study presents detailed composite profiles of temperature, moisture, and wind constructed for tornado environments in tropical cyclones that affected the U.S. between 1948 and 1986. Winds are composited in components radial and tangential to the tropical cyclone center at observation time. Guided by observed patterns of tornado occurrence, composites are constructed for a variety of different stratifications of the data, including proximity to tornadoes, position relative to the cyclone center, time of day, time after cyclone landfall, cyclone translation speed, and landfall location. The composites are also compared to composite soundings from Great Plains tornado environments. A variety of sounding parameters are examined to see which are most closely related to the tornado distribution patterns. Lower-tropospheric vertical shears are found to be stronger in the tropical cyclone tornado environments than on the Great Plains. Buoyancy for the tropical cyclone tornado cases is much smaller than that seen with Great Plains tornado events and exhibits a weak negative correlation with tornado outbreak severity.