EESA09H3 Lecture Notes - Lecture 6: Outflow Boundary, Cumulus Cloud, Wind Shear
6 Mar 2020
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Document Summary
Surface heating induces upward flow, cumulus cloud formation. Mature phase - development of a downdraft with precipitation. Gust front(kind of sustaining the storm) develops as downdraft air spreads along horizontal surface. Warm air rises, cools and condenses, then forms cumulus clouds. When cloud formation is complete, we see precipitation this is known as the matured stage. Gust front forces more air up into the updraft. Updraft and downdraft form a convective cell. When the gust front moves past the updraft, the updraft weakens. Rain starts to fall into the updraft, cutting off rising humid air. Second stage is where downdraft is formed, gust front can sustain a storm for less than an hour. You need both updraft and downdraft for the mature stage. At the final stage downdraft cuts off updraft, and the storm loses its energy. Downdraft cuts off updraft and storm loses energy source and dissipates. It is relatively short lived < hour, diameter, 1km or less.
