Towards a Better Understanding of Convective Storm Evolution over the Coastal Northeastern U.S

Severe weather and heavy precipitation associated with warm season organized convective storms can result in catastrophic damage along the densely populated northeastern U.S. coastal region. Both storm development and evolution have been shown to be influenced by the complex urban-coastal environment, especially in the tri-state region, including northern New Jersey (NJ), New York City (NYC), Long Island (LI), and southern Connecticut (CT). The varying thermodynamic and dynamic conditions across the land-ocean boundary can modify ongoing organized convective storms moving into this region. For example, our previous research has shown that on average, quasi-linear convective systems (QLCS) moving from inland areas can persist crossing over coastal waters in the presence of low-level warm air advection and moderate (13.5 m s-1) 0-3 km vertical wind shear. Conversely, those that decay crossing over the coastal waters are typically associated with surface cold fronts and less robust (7.4-10.7 m s-1) low-level vertical wind shear.

Numerical simulations of individual QLCS case studies support these conclusions and provide some insight into the physical processes associated with sustaining and decaying lines of convection. For example, a simulated sustaining QLCS became slightly elevated above a relatively deep stable marine layer enhanced by low-level warm advection, while the source of air ingested into a decaying QLCS was surface-based. While these previous studies provide some insight into the evolution of QLCSs in a coastal environment, more research is necessary to more deeply understand the processes that control the evolution of these storms, including additional numerical process studies as well as acquiring high-resolution data to evaluate and verify numerical analyses.

This past summer (17 June – 8 July 2013), the field component of the Doppler Radar for Education and Mesoscale Studies (DREAMS) project was executed on Long Island, NY. DREAMS is a collaborative project between Stony Brook University, the National Weather Service (NWS) located in Upton, NY, and the Center for Severe Weather Research (CSWR) located in Boulder, CO. The fundamental goals of the project are threefold: (1) to educate students on local meoscale weather phenomena while gaining experience utilizing state of art research radar equipment and data (2) to obtain high temporal and spatial resolution data sets of local mesoscale weather phenomena (3) to expose the broader public to the latest atmospheric research including many of the challenges encountered when forecasting the local weather.

In addition to the primary goals of the project, this field study provided an opportunity to obtain valuable data sets of local convection using cutting edge radar technology (i.e. Doppler on Wheels) in concert with in situ observations. The poster will highlight observed cases of local convection placing them in the context of the latest understanding of coastal convection, while discussing opportunities for further advances based on this knowledge.