3A.1 An Overview of Mesoscale Convective System Observations During the Plains Elevated Convection at Night (PECAN) Field Campaign

Monday, 11 January 2016: 4:00 PM
Room 344 ( New Orleans Ernest N. Morial Convention Center)
Russ S. Schumacher, CSU, Ft. Collins, CO; and M. C. Coniglio, S. M. Hitchcock, M. D. Parker, C. Ziegler, and M. Biggerstaff

The field phase of the Plains Elevated Convection At Night (PECAN) field experiment took place from 1 June--15 July 2015, with observations collected from a diverse array of fixed and mobile instrumentation. One of the scientific objectives of PECAN was improving understanding and prediction of nocturnal mesoscale convective systems (MCSs) and their interactions with the stabilizing nocturnal boundary layer. During PECAN, MCSs of varying levels of organization were observed, from well-formed squall lines to weakly organized convective lines and clusters. This presentation will provide an overview of data collection strategies and preliminary analyses of these MCSs. In particular, we will focus on four nocturnal MCSs that were expected, based on their mesoscale thermodynamic and kinematic environments, to produce widespread severe winds, but instead produced no or only localized severe winds. Because the question of whether "elevated" MCSs will produce severe weather at the surface remains a challenge in terms of both scientific understanding and operational forecasting, these observations may yield important insights into the processes that support or inhibit the development of severe surface winds. Using mobile sounding observations at high temporal resolution, fixed and mobile radar observations, and numerical simulations, we will assess the respective roles of thermodynamics, vertical wind shear, cold-pool properties, and synoptic-to-mesoscale forcing in the organization and evolution of these four MCSs.
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