[1] Several urban centres and towns in Southland including Invercargill, Riverton, Bluff, Otautau and Tuatapere experienced significant flooding.

[1][3] According to the National Institute of Water and Atmospheric Research (NIWA), the lower South Island experienced a strong north-westerly airstream between 26 and 28 January 1984.

NIWA believed that the frontal band had originated in the tropical regions of north and north-western Australia.

While the Canterbury and Otago regions also experienced heavy rainfall, the Southland and Fiordland bore the brunt of the wet weather front due to a deep layer of humid air during a 36-hour period between 26 and 27 January.

In Southland's high country areas, the hills and mountains were inundated by the moist north-westerly airstream.

This weather flow was met by a southerly front, resulting in heavy rainfall in the lower-lying parts of Southland.

Throughout the day the rain got stronger, and after meeting with a southerly front, the streets of Invercargill, Riverton, Bluff, Otautau and Tuatapere started to experience surface flooding at about 9 pm.

[2][3] At one point, Invercargill Airport was 3 metres (9.8 ft) deep in water and 10 aeroplanes were partly submerged.

[7][1] In terms of transportation, all of Southland's roads and railways were flooded, cutting the region off from the rest of the country and 100 bridges were also damaged.