A Convective Line with Leading Stratiform Precipitation from BAMEX

Authors

Brandom Storm, University of Nebraska—Lincoln & Texas Tech University, LubbockFollow
Matthew D. Parker, North Carolina State University, Raleigh
David P. Jorgensen, NOAA/NSSL/Warning R&D Division, Norman

Document Type

Article

Date of this Version

2006

Citation

2007 American Meteorological Society

Comments

MAY 2007 STORM ET AL. 1769-1785

DOI: 10.1175/MWR3392.1

Abstract

On 31 May 2003, a front-fed convective line with leading stratiform precipitation (FFLS) was observed during the Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX). The high-resolution BAMEX measurements provided one of the first opportunities to thoroughly observe the characteristics of an FFLS system. The 31 May system had an overturning updraft during its early stages, and produced leading stratiform precipitation. As the system matured, a jump updraft developed and the system began to produce trailing stratiform precipitation. It appears that this transition was facilitated by a local decrease in the low-level line-perpendicular vertical wind shear over time, as well as an increase in the surface cold pool’s strength. The BAMEX data further help to address the question of how FFLS systems can be long lived when their inflow passes through the line-leading precipitation: preline soundings suggest a destabilization mechanism resulting from the vertical profile of cooling within the leading stratiform precipitation. This destabilization also helps to explain the 31 May convective system’s persistence in an environment with very low CAPE.