Sunday, 22 January 2012
A Statistical Spatial Mesoscale Analysis of Tornadogenesis Along CAPE Gradients
Hall E (New Orleans Convention Center )
Tornadogenesis has baffled forecasters for decades, and although much research has been completed exploring this very topic, many questions remain unanswered. For instance, is there a preference as to where tornadogenesis occurs in relation to the convective available potential energy (CAPE) axis? Using archived 40km Rapid Update Cycle (RUC) data from the Storm Prediction Center and tornado reports from the National Climatic Data Center, days where at least one tornado occurred in Iowa, Illinois, and Missouri over a period from 2006-2010 were analyzed to explore this question. First, the CAPE axis was defined, and then the distance between the axis and the tornado report calculated as well as where the report occurred in relation to this axis. Statistical analysis then determined whether a preference existed for tornadogenesis in relation to the axis and established the significance of the result. An analysis of the mesoscale environment on each side of the CAPE axis was then carried out using severe weather parameters, e.g. storm-relative helicity, bulk shear, lifting condensation level heights, to explore the physical reasons determining this preference.