The first day of summer has produced supercell thunderstorms over northeast New South Wales and southeast Queensland. Storms exploded over the region from 3pm EDT today and quickly intensified while moving towards the north and northeast. In the mix today were two rotating supercell thunderstorms, which are the most intense and dangerous type of storm. One supercell ploughed through the Northern Rivers district in New South Wales, clipping Casino, Kyogle and Nimbin. The second one further north formed near Esk, before heading up towards Woodford and Maleny. Warnings for destructive winds, giant hail and heavy rain were issued as the first day of summer put on an epic show for storms chasers in the region. Initial observations included golf to tennis ball sized hail at Peachester and Kyogle. While the storms were roaring further south and north, sky gazers in the Gold Coast area were lucky enough to witness rare mammatus clouds. These pouch-like clouds form as cold air sinks through the atmosphere and are known to develop in the vicinity of storms. Severe storms will continue during coming hours. The latest severe storm warnings are available here: http://www.weatherzone.com.au/warnings.jsp