Observation and Modeling of Split Summer Thunderstorms Over New York City

The research presented here is directed towards determining the effect of urban environment on storm development. It is known that urban environments influence precipitation by splitting intense storms. An explicit microphysics model coupled to the Regional Atmospheric Modeling System (RAMS) was used to represent two summer precipitation scenarios for NYC. This research aims to track the development of the two storms, one of which is localized and one of which is a Mesoscale Convective Complex (MCC) influenced by large scale factors. In situ aerosol PSD data from NASA's AERONET sunphotometer network were processed and ingested directly into RAMS to represent Cloud Condensation Nuclei (CCN) and initiation of microphysics for the selected events. The city was represented by high resolution land data acquired from the United States Geological Survey (USGS) updated in 2006. Anthropogenic heat from buildings and traffic were included in the urban parameterization. Model results suggest that the city acts to shape spatial precipitation patterns by suppressing rainfall over the city while enhancing rainfall downwind.