WSR-88D Observations of Mini-supercells in Tropical Environments

Tropical environments that support tornadic mini-supercells typically consist of deep moisture, weak instability, strong low-level shear and weak deep-layer shear. While such environments are often found near tropical cyclones, mini-supercells have also been documented in similar environments over the Midwest. Although these storms commonly occur, they have not been subject to many detailed radar analyses beyond mesocyclone structure and storm depth. This is despite the damage that tornadic mini-supercells can cause and the challenges they pose to warning decision making.

This study presents observed WSR-88D signatures of mini-supercells from several tropical cases, including cases near tropical cyclones and similar environments over the Midwest. Features commonly observed with these storms will be discussed, including mid-level velocity maxima, rear-flank divergent signatures, hook echo structure, and in some cases, what may be descending reflectivity cores. Possible implications of some of these features to the presence and/or formation of a rear-flank downdraft will also be discussed.