Total lightning for early warning: the tornadic supercell with giant hail on 6 July 2023

Abstract

On 6 July 2023, a severe thunderstorm outbreak took place in the NE of the Iberian Peninsula. Severe weather was reported between 12:00 and 21:00 UTC, from large-to-giant hail, flash floods and strong convective winds. We focus our analysis on the Mid Ebro Valley, south of the city of Zaragoza, where giant hail was recorded (ø > 10 cm) along with damaging winds (i.e., an IF1.5 tornado and three IF2 non-tornadic events). This case study helps us to demonstrate the advantages of integrating Lightning Mapping Array (LMA) real-time data along with radar and satellite products for severe weather surveillance. Although total lightning signatures are less common to forecasters, they complement those observed by the radar and satellite, enhancing their confidence in the decision-making process and triggering warnings of possible severe weather. In the present case study, prior to the severe weather reported at the ground, a long-lasting “lightning hole” signature was observed in the LMA, collocated with the BWER radar signature, along with “sparkles”, high-altitude LMA sources (15–16 km), suspended 2 km above the bulk of the lightning occurring in the overshooting tops of the storm, indicating deep-moist convection. Compared to the lightning “jump” pattern, these LMA signatures provided a longer lead time.