One focus of the recent International Water Vapor (H2O) Project (IHOP-2002) was to learn how water vapor, temperature, and airflow in the boundary layer control the initiation or suppression of deep, moist convection. The first two authors (CZ and ER) developed testable hypotheses relating cumulus and storm development to updrafts and mesoscale vortices and the levels of moist convective instability and wind shear in the boundary layer.

Detailed mobile 2- to 4-radar observations of the boundary layer across a dryline, cold front, and their triple-point intersection were obtained every 3 min during the IHOP mission of 24 May 2002. Dual- and multi-Doppler radar analyses track the movement and evolution of boundary layer updrafts and mesovortices over a 2 hour period within the intensive observing region (IOR). GOES-8 visible satellite imagery is remapped to the radar analysis domain, permitting statistical cross-correlation analysis of cumulus development to radar-derived and other boundary layer features. Objective analyses of water vapor, virtual temperature, and instability are derived from mobile mesonet and aircraft traverses and mobile and dropsonde soundings in the IOR using a new Lagrangian technique based on the multi-Doppler wind field. The combined analyses are used to test our hypotheses concerning the timing and location of cumulus clouds and storm suppression.