We have undertaken a study of the "Owl Horn" signature using the Tracking Radar Echoes by Correlation technique (TREC). While TREC has previously been applied to clear air and hurricane environments (Tuttle and Foote, 1990; Tuttle and Gall, 1999), absent from the literature is an application of TREC to severe storms and supercell storms in the interest of studying supercell evolution, although Rinehart (1979) has previously studied internal storm motions by applying TREC to severe storms. Through the application of TREC to our radar reflectivity data (Doppler wind data were not available in 2001) during May and June, 2001, we computed an estimate of the horizontal wind field around and in the "Owl Horn" signature. TREC revealed the presence of a wind shift line, coincident with the signature in the reflectivity.
Recently, we have found evidence of the “Owl Horn” signature in numerical model simulations as well, which has enabled us to examine both the simulated ambient atmospheric parameters during the signature’s presence, as well as the sensitivity of the “Owl Horn” to changes in those parameters, primarily the environmental wind shear. In this paper we present results of our TREC analysis and model simulations, and speculate as to the conditions in which the “Owl Horn” echo forms.
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