Oklahoma Thunderstorms on 29–30 April 1970. Part IV: Study of a Dissipating Severe Storm

Abstract

A small dissipating hailstorm entered the National Severe Storms Laboratory surface and upper air networks about 1800 CST 29 April 1970. Structural details revealed by radar and network observations indicate that the storm was a nascent supercell at one time, but that weak thermal instability, limited low-level moisture and adverse upper winds prevented the storm from reaching the damaging proportions of later storms on this date. A surprising surface pressure distribution—high pressure center near the updraft and strong pressure gradient beneath the downdraft—suggests that the storm interacted to its detriment with a larger scale, wavelike perturbation.