A diagnostic analysis of the 30 May 1967 squall line in Central Oklahoma

Abstract

A squall line is investigated during a 3-hour period of its mature life. Upper air data from the mesonetwork in Oklahoma at 1700, 1830, and 2000 GMT is used to determine vorticity, divergence, and vertical motion at 30 mb intervals. These and other fields are computed and investigated in detail, and possible problems associated with time are discussed. The methods of computing vertical motion are described in detail. A mesoscale wave with a wavelength of approximately 90 n.m. is found at 700 mb. It moves faster than the wind at 700 mb but slower than at the squall line. This wave is investigated in detail and is hypothesized to be the cause and the terminator of the squall line. The kinematic vertical motion technique presented appears to give realistic fields. Appenddix B describes the problems found in the vorticity method and how it can be used on the synoptic scale.