The Principal Investigator will use existing observational data and a state of the art mesoscale numerical model to investigate a wide range of convective phenomena such as squall lines, severe storms, convective turbulence, tornadoes and gust fronts. The objective is to advance fundamental understanding of the dynamics and physics associated with these events with the ultimate goal of providing guidance which will assist in more accurate prediction of severe weather events. Specific objectives include: (1) determining the dynamics and accompanying environment of long-lived tornadoes; (2) investigating the convective behavior of an observed squall line through the use of a hydrostatic regional model coupled to a nonhydrostatic convection model; (3) understanding the role of boundary-layer convergence/shear boundaries in the generation of non-supercell tornadoes; (4) probing the behavior of individual convection within mid-latitude squall lines simulated in environments with horizontal variability; (5) exploring the dynamics of turbulence under dry, moist, and precipitating conditions through simulation of the multiple scales involved; and (6) further development of the modeling, analysis, and visualization for studying convection.