The Czech weather radar network, consisting of two Doppler C-band weather radars [Gematronik Meteor 360 AC, EEC DWSR-2501C], has been upgraded by an independent in-house software package for volume data processing and visualization. This new software offers wide range of reflectivity and Doppler velocity products, enabling storm structure studies with 1km (or better) spatial resolution.

JavaScript based viewer (JSMeteoView) has been developed for versatile visualization of radar and other meteorological data in the Internet/Intranet environments. The JSMeteoView is designed to enable combination of the following data sources: <

• Czech weather radar network products
• Meteosat IR imagery
• Central European Lightning Detection Network data
• NWP LAM outputs
• Geographical navigation

The software package is recently under implementation in the Czech Hydrometeorological Institute (national weather service of the Czech Republic). Examples of radar products and their graphical presentations are shown on a case of tornadic storms of the May 31, 2001.

Several convective storms passed in strong westerly flow over the territory of the Czech Republic during the afternoon of May 31, 2001. Two of these storms were documented as tornadic. The most intense tornado of that day was about F3 (one of the strongest on territory of the Czech Republic in recent years), with a life-time of about 15 minutes. The tornado's parent storm, the tornado itself and its damage path were extensively documented.