In situ measurements within an F4 tornado.

摘要

On 24 June 2003, in-situ probes were deployed in advance of an F4 tornado near Manchester, SD, successfully measuring pressure, temperature, and relative humidity. This tornado was spawned as the result of a favorable supercell merger and the translation of the supercell along the warm front. Probe 3 experienced a direct hit and measured a 100 mb pressure drop. A damage survey and photogrammetric analysis were conducted and substantiated the validity of using cyclostrophic balance to approximate a maximum tangential wind speed of 92 m s-1. Probe 5 measured a 54 mb pressure deficit, but passed approximately 10 meters from tornado path axis. A new pressure trace was prepared assuming the probe passed through the center of the vortex yielding a 62 mb pressure drop. Cyclostrophic approximation was utilized to estimate the maximum tangential wind speeds of 78 m s-1 and compared with the photogrammetric analysis, which demonstrated reasonable correlation.