Bureau of Meteorology senior forecaster Chris Godfred said "the image that launched a thousand memes" was actually a fairly common phenomenon. He said when a rain-producing weather system met a downward flow of air, it meant the rain was less likely to fall and instead created a "rain shadow".

"It is quite common, but I think in this case the radar just picked up the image particularly well," Mr Godfred said.

The storm's video game doppelganger in action.

Once the wind changed direction, the rain became more than just a shadow and started pelting the city from about 10pm.

The eastern suburbs copped about 10 millimetres of rain overnight while the CBD recorded six millimetres.