Extreme Low-Level Downdrafts in Tropical Cyclones Measured by Dropwindsondes

Since 1997, about 100 dropwindsonde profiles within tropical cyclones have sampled downdrafts with wind speeds in excess of 8 ms-1. Unlike the fastest horizontal and upward vertical wind speeds (90 and 10 ms-1, respectively), these downdrafts occur in tropical cyclones of all intensities, and within both the core and in rainbands. A census of these observations will be presented, along with their kinematic and thermodynamic structures. The ultimate impact of these events on the intensity and structure of TCs will be discussed.