Applications of radar and lightning information for severe weather forecast and protection in the south of Brazil

Integrated information from weather radars, lightning detection and satellite systems are the primary tools for severe thunderstorm analysis and nowcasting. The combination of radar products such as reflectivity and precipitation estimates with lightning data and satellite images provides improved thunderstorm identification and analysis of storm characteristics and life cycle which can be used for forecasting. Recent studies with lightning observations have shown that, in South America, southern parts of Brazil and northeastern Argentina are regions particularly prone to severe weather events (high lightning activity, intense precipitation, hail, flash floods, strong winds and tornadoes), mostly related to several manifestations of mesoscale convective complexes which occur in this area mainly during spring and summer. This paper presents results from a study using SIMEPAR's Doppler weather radar, lightning detection system and satellite for the analysis of electrical and hydrometeorological characteristics of severe storms, specially with hail and intense precipitation observations during events in the south of Brazil. Although predominantly negative CG mesoscale convective systems are common, positive CG storms such as the leading line trailing stratiform squall line presented here are related to strong severe weather events and are not uncommon in this region. Radar data is presented with improved information when the system is integrated. Trend information obtained from this combination is used for thunderstorm nowcasting and verification of this technique will be presented. This paper also describes the experience of using radar and lightning data integrated for severe weather monitoring and forecasting in a meteorological operational center, located in a area prone to hazardous weather events. With a strong interest in research and development of applications for severe weather analysis and forecasting and its operative usage, tools for the integration of radar, lightning and satellite information were developed for nowcasting purposes, but also applications for management and distribution of these information for several operative end users, such as analysis and correlation of severe events and power supply faults. The result of these development are routinely used during nowcasting activities, specially related to preventing damages and injuries, and also disruptions in transmission lines and power system in the south of Brazil and also for civil defense. With this work, we expect to have a better understanding and improvement of our forecasting abilities related to those storms with strong precipitation and lightning. The integration of observation systems in an operational environment such as described in this paper is the initial step to achieve these goals.