Benefits Of Running Convection Allowing Models ( Cams ) For Convective Storm Prediction
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The benefits of running convection-allowing models (CAMs) for convective storm prediction have been demonstrated in a variety of contexts over the past decade (e.g., Done et al. 2004; Kain et al. 2006; Lean et al. 2008; Kain et al. 2008; Clark et al. 2009; Coniglio et al. 2010; Schwartz et al. 2009; Sobash et al. 2011; Clark et al. 2010, Clark et al. 2011; Weisman et al. 2013). As these studies show, much of the value of running CAM forecasts comes from their ability to provide explicit information about convective properties such as initiation, mode, motion, longevity, and intensity. To effectively use CAM output in operational forecasting settings, novel forms of guidance are needed to summarize these forecast attributes in ways that can be easily understood by forecasters and other end users.
Toward this end, Sobash et al. (2011), hereafter S11, documented a proof of concept for producing a next-day (12 UTC to 12 UTC) severe convective weather guidance product using output from deterministic CAM forecasts initialized at 00 UTC. In S11, locations where intense simulated convective storms occurred were identified using updraft helicity (UH; Kain et al. 2008), a diagnostic designed to detect mid-level mesocyclones in CAM output. A threshold was applied to the UH field to identify “severe” simulated convection and produce a field of “surrogate” severe weather reports, which were then spatially smoothed to create a surrogate severe probabilistic forecast