Highly populated areas of the Brisbane, Gold Coast and northern Rivers area received flooding rainfall over the last few days.

A low pressure trough interacting with moist coastal air has brought widespread rainfall and severe thunderstorms to NSW and Queensland since Thursday.

Over the span of a few hours early on Saturday morning, numerous places across the region saw rainfall totals reach the 100mm mark, some completely overshooting it, reaching up to 300mm. In the 24 hours to 9am on Saturday, Miami on the Gold Coast received a total of 305.6mm. In the same period of time, the Gold Coast Seaway received 254.8mm, with over 150mm falling in between 2:30am and 6:30am. This is the heaviest 24hr rainfall since June 2005 (350.8mm) and heaviest January 24hr rainfall in 21 years. 

A similar story happened at Coolangatta Airport, where a total of 205.6mm of rain fell in the 24hr to 9am on Saturday. The majority of this precipitation fell between 3am and 7am, with 177.8mm falling over this period. This is also the heaviest January rain day in 32 years.

Other significant rainfall totals in the 24 hours to 9am Saturday include: 145.8mm at Sunshine Coast Airport, 141.4mm at Redland (Alexandra Hills) and 71.6mm at Brisbane. In NSW, Tweed Head saw 195mm, Grafton Airport 155mm and Lismore Airport 128.6mm.

While the southeast of QLD and the northern Rivers in NSW received the heaviest falls on Saturday morning, other regions were affected in the following 24 hours, most notably the Central and Northern Queensland coasts. In the 24 hours to 9am on Sunday, Lockhart River received 207.0mm, while many other locations in the region received healthy totals of 30-40mm.