Analysis of Central U.S. Deep Convection Initiation Environments

Initiation is the part of the convective life cycle which is currently least understood and least well forecast. The inability to properly forecast the timing and/or location of deep convection initiation (DCI) degrades forecast skill, especially during the warm season. To gain insight into what atmospheric parameters distinguish areas where storms initiate from areas where they do not initiate, all thunderstorm initiation points over the central United States from 2005-2007 are found and a number of thermodynamic and kinematic parameters are computed from 20-km RUC-2 data. In addition to the initiation points, data are also collected at nearby locations where thunderstorms did not initiate (null events) for comparison. Thunderstorm identification and tracking are done using several tools within the Warning Decision Support Services – Integrated Information (WDSS-II) package and a thunderstorm tracking algorithm called Thunderstorm Observation by Radar (ThOR). The parameters being examined are intended to represent four of the main factors governing the behavior of convection – buoyancy, inhibition, dilution, and forced ascent. Statistical analysis of the data will show which parameters are most useful in distinguishing environments that initiate deep convection from those that do not. Analysis of preliminary results is underway and final results will be presented at the conference.