Brisbane Prepares for Worst Floods in 120 years

Irish Weather Online's Fergal Tierney writes:

The heavy rains that have claimed 10 lives in the eastern Australian state of Queensland are set to continue over the coming days, with the focus now shifting to the city of Brisbane and its two million inhabitants. The Lord Mayor estimates 6500 homes and businesses will be flooded, with 14,500 more partially affected by flood levels that are expected to reach 4.5 metres in downtown Brisbane on Wednesday and Thursday.

But why has there been so much flooding in eastern Australia of late, with over 800mm (>4 times the average) of rainfall already registered in southeastern Queensland? Map. It is due to the strong La Niña that is currently in force. La Niña, the sister of the more famous El Niño, is a strong cooling of the central and eastern Pacific waters, with corresponding warming occuring in the waters off eastern Australia. This warming leads to lower atmospheric pressure and consequently enhanced rainfall in the area. There has been a strong La Niña in place for the past few months, and it is forecast to continue well into the middle of the year. This could spell a continuation of the wet weather through the rest of their summer and autumn.

The current synoptic map, showing the extent of the low pressure areas to the north and east, with a warm humid northeasterly airflow affecting Queensland.

Follow the flood live here.