Convection initiation on 12 June 2002 during IHOP_2002

The International H2O Project (IHOP_2002) was designed to sample the three-dimensional time-varying moisture field to better understand convective processes. Numerous research and operational water vapor measuring systems and retrievals were operated in the U.S. Southern Great Plains from 13 May to 25 June 2002. This was done in combination with more traditional observations of wind and temperature. Convection initiation (CI) missions were designed to maximize observational overlap from multiple instruments to better understand the processes leading to the development of deep, moist convection. This particular study examines the impact of multiple features upon a convection initiation event on 12 June 2002. The resulting storms intensified and produced damaging winds and hail. The various clear-air features potentially affecting initiation on this day include a dryline, an outflow boundary and their intersection, a developing mesocyclone, internal gravity waves and horizontal convective rolls.

Many unique instruments were positioned to sample the pre-convective environment on 12 June 2002. The ELDORA airborne Doppler radar, Leandre II water vapor DIAL and P-3 in situ measurements provide information on the kinematic and moisture distribution along the boundaries. Several other mobile datasets are included in this study: a mobile radiometer; University of Wyoming King Air in situ instruments; Mobile Integrated Profiling System (MIPS); radiosondes and dropsondes. Although other ground-based sensors (i.e., S-Pol radar, mobile radars and mobile mesonets) were farther west than the CI area, they are useful for illustrating the high-resolution boundary-layer kinematics and thermodynamics.

The combination of these high-temporal and -spatial resolution measurements provide a detailed account of interactions between the various boundaries, mesocyclone, waves and rolls and their impact upon convection initiation. The objective is to improve our understanding regarding the critical features that are influencing the timing and location of new convection on this day.