The three-dimensional structure of a dryline observed over the Oklahoma panhandle during the International H2O Project (IHOP) on 11 June 2002 is presented. The major observational tools employed in this study include ELDORA airborne Doppler radar, Learjet dropsondes, NCAR mobile GLASS soundings, DRI microwave radiometers, NCAR S-POL radar as well as conventional weather observations such as satellite imagery and surface observations. The dryline was associated with impressive cloud line but failed to initiate storms inside the IHOP Intensive Observation Domain (IOD). Interestingly enough, convection was initiated both north and south of the IHOP IOD.

Detailed structure of 11 June dryline exhibits similar characteristics of a typical retrogressing dryline in the late afternoon over west Oklahoma. Significant along-line variability on vertical vorticity and velocity are also noticed. Several local maxima of vertical vorticity and velocity along the dryline are apparent throughout the data collection period. It is speculated that the reason why storms did not initiate along the dryline inside IHOP IOD is because the upward motion produced by the boundary was too weak to lift the air above Level of Free Convection (LFC). Further studies are needed to figure out why storms formed both north and south of the IHOP