The Superior, Nebraska, Supercell During BAMEX

Abstract

Two remarkable supercell storms developed on 22 June 2003 in eastern Nebraska. One of the thunderstorms, located near the town of Aurora, Nebraska, produced the largest known hailstone on record. Receiving far less attention was an adjacent supercell that was equally impressive and is referred to as the Superior, Nebraska, supercell. The two supercells formed during the Bow Echo and Mesoscale Convective Vortex (MCV) Experiment (BAMEX), operated in the spring and summer of 2003. One of the main platforms used during BAMEX was the airborne Electra Doppler Radar (ELDORA). ELDORA was deployed on the Superior supercell several hours after it initiated. Striking in one of the flybys past the storm was the characteristics of the parent circulation. The Superior supercell was associated with a mesocyclone that was the largest (?9 km in diameter) and the most intense (118 m s?1 velocity differential) ever documented. Ground-based observations from a nearby Weather Surveillance Radar-1988 Doppler (WSR-88D) located in Hastings, Nebraska (UEX), could not resolve the Doppler velocities correctly owing to the intensity of the mesocyclone. The environmental conditions, satellite imagery, and Doppler radar observations of this supercell are presented.