21st Conf. on Severe Local Storms and 19th Conf. on Weather Analysis and Forecasting/15th Conf. on Numerical Weather Prediction

Thursday, 15 August 2002: 1:59 PM
The Lamar Colorado tornadic event: A Boundary driven singificant tornadic storm in a high CAPE/low shear environment (Formerly paper P11.2)
Stephen J. Hodanish, NOAA/NWS, Pueblo, CO; and J. M. Davies
Poster PDF (563.7 kB)
On 29 May 2001, an isolated convective updraft developed on a well defined boundary, producing a total of 7 tornadoes in a two hour time period in the vicinity of Lamar, Colorado. The first through sixth tornadoes associated with this updraft were non supercell tornadoes, producing little damage (F0). The seventh tornado was supercellular in nature, and produced F3 damage. This F3 tornado was relatively long lived, remaining on the ground for 30 minutes. During the time of non supercell and supercell tornadogenesis, the storm remained stationary while interacting with the boundary. CAPE in the near storm environment was large, greater than 3000 J/Kg. Once the storm moved off the boundary, tornadogenesis ceased.

It is believed the boundary, in combination with the high CAPE, played a critical role in the development of non-supercell and supercell tornadoes. This combination of parameters also likely played a role in the motion of the storm (or lack thereof). Data from the Granada wind profiler, 27 kilometers from the storm, will be examined to compare forecast storm motion versus actual motion of this storm. A variety of shear and thermodynamic parameters will also be examined.

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