Diagnosis of a Jet Streak in the Vicinity of a Severe Weather Outbreak in the Texas Panhandle

Abstract

This is a case study of the synoptic and mesoscale aspects of a severe-weather outbreak in the Texas Panhandle. We offer circumstantial evidence that the rising branch of a thermally indirect circulation in the exit region of an unusually intense upper-level jet streak played a role in storm formation and sustenance. The jet streak's vertical circulation could not be accounted for by straight dynamics alone; curvature was important, especially along the right side of the exit region. The geostrophic momentum approximation leads to a reasonable qualitative explanation of the ageostrophic circulation, while quasi-geostrophic theory does not.