Surface-Atmosphere Couplings and Convection Processes

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Deep convection initiation (DCI), the initial stage of most summer severe weather, is one of the most perplexing and complex issues in meteorology today - the prediction of if, when and where DCI takes place generally has low accuracy. Numerical weather prediction models also have significant difficulties in predicting the timing and location of DCI. Improving predictions of DCI and associated atmospheric conditions will ultimately improve severe weather warnings (mode, severity, location and lead times). These statements apply to both daytime and overnight convection. Given this, the research questions to be addressed in this proposal are: (1) What is the sub-hourly and diurnal evolution of wet-dry vegetation regions, how do they interact and impact DCI? (2) What are the detailed characteristics of lake breezes and how do they impact DCI in Manitoba? (3) What are the characteristics, leading up to and during, warm frontal elevated DCI? (4) What are the implications of (1) - (3) for weather prediction and climate studies? Questions (1) - (4) will be addressed by doing detailed field measurements with recently acquired (and pre-existing) equipment that will provide high-resolution (spatial and temporal) profile measurements of temperature, moisture and wind in three different locations as well as surface mobile transects. The research will be done in collaboration with national and international projects that will share many other datasets (e.g. research radars, aircraft, satellite, other special ground-based remote sensors, and special surface and upper air observations) to address the three questions. The results of this work will offer recommendations for the prediction of DCI over appropriate time scales.