Mesoscale Convective Complex versus Non-Mesoscale Convective Complex Thunderstorms: A Comparison of Selected Meteorological Variables.
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A comparative investigation of mesoscale convective complex MCC and non-mesoscale convective complex non-MCC prestrom environments is conducted. Eleven atmospheric variables normally associated with thunderstorm formation are either observed or calculated for a total of nine MCC and nine non-MCC storms. These variables include 850 mb mixing ratio, 850 mb advection of water vapor, 850 mb flux divergence of water vapor, surface to 500 mb average relative humidity, precipitable water, surface to 500 mb average relative humidity, precipitable water, the Totals, Index, the Total Energy Index, 1000-700 mb thickness advection by the 850 mb wind, 500-300 mb thickness advection by the 400 mb wind, vorticity advection at 500 mb, and vertical velocity at 700 mb. Mean values are calculated for the eleven variables according to storm type. Then, the mean values from the MCC cases are compared statistically with the corresponding non-MCC values. Results show that a significant difference exists for the following mean values 850 mb mixing ration, 850 mb advection of water vapor, precipitable water, Total Energy Index, and 1000-700 mb thickness advection. The low-level water advection and thickness advection variables are combined to form a low-level energy rate of change term. This energy rate of change term is found to provide an even better distinction between MCC and non-MCC storm environments.
- Atmospheric Physics