Case study of Mesoscale Convective Systems over Hungary on 29 June 2006 with satellite, radar and lightning data

摘要

On 29 June 2006 two Mesoscale Convective Systems (MCS) crossed Hungary causing severe weather, heavy precipitation, hail and strong wind. The first MCS transformed to a Mesoscale Convective Vortex (MCV) in its dissipating phase. The case was analyzed using different remote sensing devices: satellites, radars and a lightning detection system. Visible images from the METEOSAT-8 satellite were used to discriminate thin and thick parts of the anvil and to identify the overshooting tops. Structures like cold rings and cold-U/V shapes detected from infrared imagery indicate possible penetration of the storm top into the tropopause or lower stratosphere. The near and medium infrared solar channels (and some thermal IR channel differences) provide information on cloud top microphysics. The spatial distribution of the cloud top ice crystal size was investigated with the use of the so called "convective storms" composite imagery obtained from brightness temperature and reflectivity differences of water vapor, infrared and short-wave channels. The MODIS band 1 (0.645 μm) image of the TERRA satellite shows gravity wave generation at the top of the thunderstorm cloud, which could be connected to the strength and pulsations of the updraft. Satellite images were overlaid with radar reflectivities, which are characterized by an asymmetric bow echo. It is concluded that composites of satellite, radar and lightning data help to assess relative locations of main up- and downdrafts and important features of the severe storm.