Another very warm to hot and humid day across the Sydney basin provided the ingredients for more storms. The conditions were critical in requiring to overcome the cap holding the energy down across Sydney. The first storms developed southwest of Sydney and near Penrith. These obviously struggled initially. As they moved east though, they encountered an ideal environment with rich deep moisture and favourable directional low level shear. Suddenly, the storms exploded near Horsley Park. A second rain free base developed and this also let lose with a major microburst encountered. The storm complex continued to develop along a boundary that stretched north of Horsley Park. Flash flooding and extensive high rainfall of between 40 and 50mm of rain fell in the nearby Horsley Park region. 2cm hail was also reported by storm chasers in this region. Another intense cell also developed near Richmond but also dumped its load and produced further storm activity to its east. Eventually the storm complex weakened across Sydney. One of the features of this storm system was some intense lightning from well up into the anvils given the deep atmosphere.