Measuring Hailstone Trajectories with the HailSonde

<p><span>The size, shape and ground-impact location of each hailstone is characterised by its trajectory </span><span>through the parent hailstorm</span><span>. This trajectory determines whether the hailstone passes through regions of the storm that are more favorable for growth or even miss out entirely. Recent simulation-based studies have demonstrated the diversity of trajectories and how certain pathways </span><span>exist</span><span> in response to storm processes. </span><span>Hail trajectories can also be simulated from radar observations, and this has been shown to significantly improve the accuracy of the estimated ground hail swath for case studies. O</span><span>perational hail analysis techniques </span><span>currently </span><span>do not consider trajectories, leaving a degree of uncertainty when estimating ground impact. </span><span> The lack of robust observational datasets to verify trajectories is one factor that limits the transition of this new science into operations.</span></p><p><span>This talk </span><span>will </span><span>introduce an innovative approach to measuring trajectories within a hailstorm using hailstone-shaped probes called “HailSondes”. I</span><span>mprovements</span><span> in low-energy </span><span>radio</span><span>, </span><span>energy</span> <span>storage</span><span> and electronics miniaturization are combined to make this new sensor possible, which, until recently, was the realm of fantasy for meteorologists</span><span>. </span><span>HailSonde measurements will provide critical validation for the practical application radar-derived trajectories for hailstorm analysis and nowcasting, supporting the transition to future hail services and benefiting a wide range of sectors from aviation, risk management, transport and public safety. </span><span>The design challenges, simulations, prototype development and deployment of HailSondes </span><span>within field experiments</span><span> are discussed.</span></p>