Evaluation of the Radar Echo Tops in Catalonia: Relationship with Severe Weather

Abstract

Strong updrafts occur in severe thunderstorms, causing the overshooting tops, an increase in the total lightning activity, and generating a frozen drops nucleus that will produce severe weather when it collapses. The Echo Top is a measurement of the vertical development of the cloud, considering a certain reflectivity threshold: the higher the threshold value, the lower the altitude reached. The present research shows the distribution of the Echo Tops of three reflectivity thresholds (12, 35, and 45 dBZ) in Catalonia for the period 2013–2021, comparing the distribution with the maps of hail, lightning jumps, and the topography of the region. The analysis shows how the maxima occurrence of Echo Tops varies depending on the threshold, indicating that thunderstorms have an initial development at 12 dBZ in the mountainous area, while the 35 and 45 dBZ maxima are shifted to the south, in regions with lower mountains. This last maximum is nearly coincident with the region more hit by large hail.

Keywords

• echo top
• weather radar
• reflectivity
• vertically integrated liquid
• hail
• severe weather