84th AMS Annual Meeting

Tuesday, 13 January 2004: 1:30 PM
Pressure Measurements Within a Large Tornado
Room 618
Tim M. Samaras, National Technical Systems; and J. J. Lee
Poster PDF (302.5 kB)
Making accurate barometric pressure measurements in tornado cores is difficult due to very high wind velocities, heavy rain, and wind driven debris. Special consideration applies to the physical geometry of the device as the probe must remain stationary during tornado passage. The actual barometric pressure measurement within the probe represents a special challenge as wind flow over any object will decrease the barometric pressure measurement accuracy. This is especially important due to wind velocities exceeding 80 meters/second, typical of tornado cores. A specially designed hardened probe called a “Hardened In-Situ Tornado Pressure Recorder (HITPR) has been developed by the author at Applied Research Associates. The HITPR has met all of the challenges discussed, and as a result of the methodologies used, wind speed and wind direction are also derived, along with the added temperature and relativie humidity transducers. The measurement technique and actual pressure measurements of tornado cores will be presented including the 100 millibar pressure drop measured of the violent F-4 tornado on June 24th, 2003.

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