A Climatology of the South Plains Retreating Dryline

The motion of the spring and summertime southern High Plains dryline in the absence of any large-scale weather systems usually exhibits a diurnal trend. In general, this trend is described as an easterly advance of the dryline during the daytime and a westerly retreat at night. It is known that convective development often is collocated with the dryline and such development may lead to thunderstorm initiation dependent upon various airmass properties in the vicinity of the dryline. Although such development has been well documented in the case of the advancing dryline, along the retreating dryline development is scarcer and less frequently observed. This study presents a climatological study of the retreating dryline over the period of 1980-1995. Using synoptic surface data, time and space scales of the retreat are examined. The data is also used to infer the presence of thunderstorm activity along the dryline.