“Bookend Vortex” Induced Tornadoes along the Natchez Trace

Russell L. Pfost National Weather Service Forecast Office, Jackson, Mississippi

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Alan E. Gerard National Weather Service Forecast Office, Jackson, Mississippi

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Abstract

This study focuses on the evolution of the northern end of a bow echo that moved across parts of southwest Mississippi on 8 May 1995. A well-defined, cyclonically rotating “comma head echo” developed north of Natchez, Mississippi, and moved northeast for about 120 km (75 mi) before dissipating. The circulation associated with this comma head echo passed through several diameter changes during which the diameter varied between that of a classic mesocyclone and that more typical of a “bookend vortex.” The circulation and a strong rear inflow jet helped spawn small tornadoes (F0–F2) in Claiborne County, Mississippi, and wind damage in western Hinds County, Mississippi. The observed damage path from the tornadoes was more than 8 km (5 mi) long. For much of the track, the tornadoes paralleled the Natchez Trace, a scenic federal highway that extends from Natchez to Nashville, Tennessee.

Corresponding author address: Russell L. Pfost, National Weather Service Forecast Office, 234 Weather Service Drive, Jackson, MS 39208.

Email: Rusty.Pfost@noaa.gov

Abstract

This study focuses on the evolution of the northern end of a bow echo that moved across parts of southwest Mississippi on 8 May 1995. A well-defined, cyclonically rotating “comma head echo” developed north of Natchez, Mississippi, and moved northeast for about 120 km (75 mi) before dissipating. The circulation associated with this comma head echo passed through several diameter changes during which the diameter varied between that of a classic mesocyclone and that more typical of a “bookend vortex.” The circulation and a strong rear inflow jet helped spawn small tornadoes (F0–F2) in Claiborne County, Mississippi, and wind damage in western Hinds County, Mississippi. The observed damage path from the tornadoes was more than 8 km (5 mi) long. For much of the track, the tornadoes paralleled the Natchez Trace, a scenic federal highway that extends from Natchez to Nashville, Tennessee.

Corresponding author address: Russell L. Pfost, National Weather Service Forecast Office, 234 Weather Service Drive, Jackson, MS 39208.

Email: Rusty.Pfost@noaa.gov

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