Several thunderstorm supercells tore through southeastern parts of Queensland yesterday afternoon. Tennis ball sized hail clamored across the rooftops of Stanthorpe around 4:30 pm yesterday as a supercell lumbered overhead. Another thunderstorm cell hurled golf-ball sized hail throughout Ipswich, Amberly and Laidley. These storms brought frequent lightning - over 26,000 strikes were detected within a 100 km radius of the Brisbane CBD. Many people observed anvil crawlers - large tendrils of lightning that shoot out horizontally across the sky. Even though rain wasn't the main feature of these storms, several locations picked up generous totals. Amberley airport collected up 30mm, while over 50mm plopped in the bucket at Grandchester and Millbrook. A broad low pressure trough was the cause of these thunderstorms. Although these features often trigger thunderstorms, what produced these hail-bearing supercells was the strong wind sheer, cold air aloft and a dry slot of air in the mid-atmosphere. Daytime temperatures, ranging from two-to-three degrees above the November average, also gave the storms some extra energy. Severe thunderstorms continue to be a risk today for the Southeast Coast and Wide Bay and Burnett districts. From tomorrow, a high pressure ridge will maintain stable conditions until the end of the working week.