Determining the Relationship Between Cumulus Cloud Width and Radar Reflectivity Echo Size

The connection between updraft and downdraft size in cumulus clouds is an important part of weather prediction and thunderstorms. Understanding updraft width is important because of the connection between updraft width and entrainment. For instance, entrainment will have a greater negative effect on wider up drafts when compared to narrow updrafts. The larger the cloud width and updraft, the bigger the storm and potential impact. Yet updrafts are difficult to observe and measure from a single scanning radar because of variable beam angles relative to ascending air. Downdrafts, on the other hand, are readily observed by radar via the precipitation they contain because radar specifically detects the signal that is scattered back from precipitation particles. Therefore, with a consistent connection between updraft and downdraft width, radar measurements can provide better understanding of updraft attributes indirectly through observing downdrafts. In this study, the connection between updraft and downdraft width will be established through comparing updraft vertical velocities, downdraft radar reflectivity, and simulated radar attributes of cumulus clouds in a high-resolution numerical simulation.