Supercells in Environments with Atypical Hodographs

Abstract

n unusual severe weather event with supercell thunderstorms developed across portions of northern Arizona in the midst of the warm-season North American monsoon?a regime characteristically dominated by a subtropical upper-level high over the southwestern United States. The approach of a midlatitude, cold-core, upper-level low brought an environment of enhanced shear and increased instability supportive of supercells. This atypical system is described and how a correct interpretation of the winds and hodograph would allow a forecaster to maintain situational awareness is discussed.