Short-term Prediction of Weather Radar Quantities and Lightning Activity in Dallas-Fort Worth (DFW) Area

Accurate, spatially specific, and temporally extended short-term automated forecasts (nowcasts) of lightning activity are of great interest to the preservation of life and resources for a multitude of applications. This paper presents a study investigating the use of several radar-based data products to nowcast lightning activity. Previous research has shown that observations of these data products yielded lead times to lightning activity from about 0–20 min. This study investigates the extent to which nowcasts of these data products can be made to potentially extent the lead times inherently afforded by these data products.

A collection of severe storm events occurring over the Dallas- Fort Worth (DFW) Metroplex will be analyzed. Nowcasts of radar reflectivity gridded at various environmental temperature levels and thresholded at various values will be analyzed. Additionally, nowcasts of a radar-based ice mass estimate called Vertically Integrated Ice will be examined. This product provides an estimate of the mixed-phase ice mass aloft and will be investigated using original fixed, parameters gleaned from bulk microphysical studies and parameters dynamically tuned based on radar and lightning density observations.

The analysis will be done in Lagrangian space using de-cross-correlation time, or a measure of the maximum nowcasting lead time where the cross- correlation between the data product and corresponding lightning density observation decays to the point where it is no longer potentially valuable as a predictor of lightning activity. De-cross-correlation times of these radar products will be compared to decorrelation times of lightning density nowcasts to demonstrate the potential and provide a first-order approximation of the extent to which these radar-based quantities can nowcast lightning activity.