Severe thunderstorms, because of their propensity to injure, kill, and cause extensive property damage, are a primary concern to not only weather forecasters but also the public. However, these storms remain a puzzling scientific and forecasting problem, as they exhibit not only a wide range of electrical activity, but also diversity in precipitation type and amount. One of the more intriguing severe storms types in this regard is the supercell thunderstorm (Browning 1964). In its most pristine state, a supercell is a unicellular thunderstorm comprised of a single, long-lived, rotating updraft, and it frequently produces large hail, high winds, prolific lightning, and occasionally tornadoes. While the basic dynamics of supercells seem well understood (e.g, Klemp 1987), these storms exhibit a wide variety of precipitation haracteristics that are not understood. For instance, supercells have been classified as either low precipitation (LP; Donaldson et al. 1965; Davies-Jones et al. 1976; Burgess andDavies-Jones 1979; Bluestein and Parks 1983), classic or medium precipitation (MP), or heavy precipitation (HP; Doswell and Burgess 1993; Rasmussen and Straka 1998) based on visual observations of the cloud and precipitation shafts Perhaps the least-understood among these storms are LP supercells, which characteristically produce some large hail but little rain.Potentially because of the dry environment and lack of visible precipitation, the visible cloud below the anvil is a skeleton compared with other supercell storms (Bluestein and Parks 1983; Bluestein and Woodall 1990).
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