A climatology of springtime convection systems over the Northwest Gulf of Mexico and adjacent coasts

Abstract

A Springtime (March 15-June 15) climatology of Mesoscale Convective Systems (MCS) has been established on the basis of satellite imagery and radar reflectivities over the Northwest Gulf of Mexico and adjacent coastal areas during 1985-1994. The systems are tracked using hourly to half-hourly GOES-7 enhanced infrared satellite imagery. After tracking the storm's upper level cloud shield, radar reflectivities were used to classify the organization of convection within the MCS. The nine primary classes of convective structure were enhanced stratiform rain, embedded unorganized storms, unorganized storms, organized cells, solid line, symmetric line, asymmetric line, multiple convective bands, and embedded line. An examination was performed of the relationship between the synoptic-scale environment with the structure and evolution of these storms. Particular attention was given to synoptic-scale factors that affect convective organization. Climatological attributes such as diurnal characteristics and average durations were extracted from a documentation of more than 3@O meso-systems. Also, severe weather produced by the MCSs was examined. In addition, wind shear and thermodynamic parameters were analyzed during the initial phases of storm development. Since a climatological study has never been recorded for this region, the analysis will be informative for determining what type of interactions there are between synoptic scale forcing and mesoscale weather features in this area. Comparison with similar climatologies conducted in the Central Plains of the US was made to determine if MCS activity in a semi-tropical location was similar to that in more northern latitudes. Moreover, this radar climatology may be used as a resource in the planning of field experiments or operations concerning mesoscale weather throughout the southern portion of the US.