Oluwafemi Omitusa

Abstract: This study examines the behavior and microphysical properties of convective cells across different environments in the Houston metropolitan area during summer 2022. Using KHGX NEXRAD radar observations of 22,372 cell tracks, convective properties were analyzed across upwind, urban, and downwind regions. The upwind region, dominated by coastal processes, exhibited peak cell initiation during early morning hours (80% of total cells) with smaller (42.5 km²), less intense (36 dBZ) cells. The urban region showed approximately double the number of initiated cells per unit land area compared to upwind and 4“5 times more than downwind regions. Urban-influenced cells displayed greater variability in hydrometeor characteristics, larger mean raindrop sizes (ZDR ˆ¼ 1.8 dB), and higher liquid water content (KDP ˆ¼ 1.4 deg/km). Despite more frequent initiation, urban cells had lower precipitation efficiency. The downwind region demonstrated the highest precipitation efficiency (30 m m/cell) despite lower cell density. Analysis of cell lifecycles revealed distinct patterns across regions. Urban impacts persisted downstream, with cells maintaining higher intensities through mature and dissipating stages. Upwind cells showed more uniform microphysical characteristics throughout their lifecycle, while downwind cells exhibited extended vertical development of ice particles during the developing and mature stages. This research advances understanding of how urban environments alter precipitation formation mechanisms and how the combined effects of sea breeze and urban heat island influence the spatiotemporal evolution of convective storms. It also highlights the need for further investigation into the combined effects of sea breeze and urban heat island on convective storm evolution.