Mesoscale Convective Systems: Squall Lines and Bow Echos

Mesoscale convective systems (MCSs) present additional challenges and responsibilities to forecasters beyond those associated with isolated convection. Since an MCS itself is composed of a range of convective cell types, MCSs present the same severe weather threats as isolated cells, but the range of severe weather types may be broad and may exist simultaneously within the system. Furthermore, system organization enhances the potential for widespread, long-lived, damaging winds and increases the likelihood of broad-scale heavy precipitation and flash flooding. This module presents current conceptual models of several MCS types and provides explanations for the structures and behavior of MCSs based on the physical processes underlying their evolution. An understanding of the physical processes and conceptual models of MCSs will help forecasters to predict the most likely locations of severe weather within existing systems and to forecast the longevity, areal extent, and path of the system. Accompanied by conceptual animations, numerical simulations, and case studies, Mesoscale Convective Systems: Squall Lines and Bow Echoes presents strategies with which the forecaster can identify the potential for long-lived MCSs and attendant severe weather. The MCS module is available over the World Wide Web and on CD-ROM. The entire module (v. 3.0) is included on the MCS Matrix CD-ROM for user convenience. Educational levels: Graduate or professional