Characterization of Convection and Rainfall Off the Pacific Coast of Colombia Using Airborne Radar and Dropsonde Data

Abstract

The Organization of Tropical East Pacific Convection project used dropsondes deployed from high altitude and a downward-pointing W-band Doppler radar to document the characteristics of mesoscale convective systems (MCSs) located over the Pacific coastal waters of Colombia. MCSs dominated by ice crystal aggregates above the freezing level rather than graupel, as shown by the radar, are generally thought to indicate decaying stratiform rain systems with only light rain. However, dropsonde grids showed a broader range of MCS types in this category, some with shallow convection producing intense rainfall. The radar had difficulty in distinguishing between different types of aggregate-dominated MCSs.