Can high-resolution surface moisture fields be retrieved in supercells?

Previous studies have shown that the likelihood of tornadogenesis and the significance of tornadoes depend on characteristics of the moisture field. Hence, retrievals of high-moisture fields near potentially tornadic storms may be useful for nowcasting tornadogenesis. Radar refractivity retrievals could address this need, and have shown the capability to resolve small-scale moisture variations associated with numerous meteorological phenomena (e.g., drylines, outflow boundaries, convection initiation). Owing to increased variance in phase measurements in precipitation and a refractivity bias caused by propagation delay, refractivity retrievals in precipitation are typically censored. To improve phase measurements within precipitation, a weather clutter (WC) filter was designed to attenuate the precipitation signal. Applying the WC filter prior to phase estimation improved the coherence of phase measurements for poor clutter targets. To address the bias issue, a method of estimating and correcting the refractivity bias using polarimetric radar was developed. The theoretical background of the techniques will be provided along with examples of refractivity retrievals near supercells.