Discriminating between Tornadic and Nontornadic Thunderstorms Using Mesoscale Model Output

Abstract The ability to discriminate between tornadic and nontornadic thunderstorms is investigated using a mesoscale model. Nine severe weather events are simulated: four events are tornadic supercell thunderstorm outbreaks that occur in conjunction with strong large-scale forcing for upward motion, three events are bow-echo outbreaks that also occur in conjunction with strong large-scale forcing for upward motion, and two are isolated tornadic supercell thunderstorms that occur under much weaker large-scale forcing. Examination of the mesoscale model simulations suggests that it is possible to discriminate between tornadic and nontornadic thunderstorms by using the locations of model-produced convective activity and values of convective available potential energy to highlight regions of likely thunderstorm development, and then using the values of storm-relative environmental helicity (SREH) and bulk Richardson number shear (BRNSHR) to indicate whether or not tornadic supercell thunderstorms are likely....

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