A Synoptic Climatology of Warm Season Convection in the Southern Great Lakes Region

对流的频率、特征、季节性和昼夜位相是一个地方或地区气候学的重要组成部分。在这方面，对美国南部五大湖区的研究不足。它位于西部地区和东部地区之间的过渡地带，西部地区在温暖的季节以夜间雷暴为主，东部地区雷暴主要发生在白天。这使得南部五大湖的独特之处在于，在一年中温暖的月份里，夜间和白天的对流同样频繁。湖风和陆水温差的影响的性质和程度以及它们与对流的发生、时间和强度的关系在该地区尚不清楚。这项研究将利用闪电和雷达观测，在精细的时间和空间尺度上记录五大湖地区南部的对流气候学。该项目将查明夜间对流系统和日间对流系统统计特性的差异，并审查对流频率和时间变化的性质和程度。将评估形成夜间和白天对流事件的中-α尺度和天气尺度大气环境的差异。这将有助于评估对流风暴对人的生命和财产造成的潜在闪电损害和强降水可能性的相对危险。这项研究所产生的改进的对流气候学将使人们能够重新评估目前提出的对流风暴日相差异的解释。对流风暴的统计特性与其形成的大尺度环境之间所确定的联系可用于对流的短期预报。

The frequency, character, seasonality, and diurnal phasing of convection are important components of the climatology of a place or region. The southern Great Lakes region of the United States has been understudied in this regard. It lies within a transition zone separating western regions where nocturnal thunderstorms predominate during the warm season and eastern regions where thunderstorms occur mostly during the daytime. This makes the southern Great Lakes unique in that nocturnal and daytime convection are equally frequent during the warm months of the year. The nature and extent of the influence of lake breezes and land-water temperature differences and their relationship to the occurrence, timing, and intensity of convection is unknown for this region. This research will document, using lightning and radar observations, the convective climatology of the southern Great Lakes region at a fine temporal and spatial scale. The project will identify the differences in the statistical properties of nocturnal versus daytime convective systems, and examine the nature and extent of variations in convective frequency and timing. Differences in the meso-alpha scale and synoptic scale atmospheric environment in which nocturnal and daytime convective events form will be evaluated. This will assist in an assessment of the relative hazard to human life and property posed by convective storms in terms of potential lightning damage and the probability of heavy precipitation. The improved convective climatology resulting from this research will allow for a re-evaluation of currently proposed explanations for differences in the diurnal phasing of convective storms. The linkages identified between the statistical properties of convective storms and the large-scale environments in which they form can be employed in the short-range forecasting of convection.