The Development of Severe Convection Along a Dry Line in Northern Arizona

On the evening of 01 July 2013 a series of mesoscale convective systems developed across northern Mexico. These produced substantial cold pools containing high theta-e air that surged northward into southern Arizona. The leading edge of this outflow produced additional convection over southern Arizona that, again, produced a northward moving surge of high theta-e air. This surge of moisture made it as far north as the higher terrain of the Mogollon Rim of northern Arizona.

On the afternoon of 02 July 2013, strong-to-severe convection developed along the moisture boundary. During the course of the day, the moist surge retreated to the south. With deep-layer northerly flow aloft, storms that developed along this dryline-like boundary moved southward and into the lower elevations while remaining in close proximity to the dryline.

This pattern is similar to that which can occur in the central Plains of the United States as large mesoscale convective systems produce cold pools and outflows that progress westward into the much drier higher-elevation regions of the High Plains. Comparisons will be made between the dryline convection in these two very different locations.