Cyclone Wilma battered the Far North. Photo / Peter de Graaf
North Island east coasters live in the country's most cyclone-prone area - and there could be more to come this year, say experts.
About 200 scientists from Australia and New Zealand gathered in Wellington this week for a three-day conference on extreme weather patterns.
One of those trends discussed was
tropical cyclones, something that battered eastern Northland, Auckland, the Coromandel and Bay of Plenty last month. Torrential rain and severe gales hammered the regions when they were hit by tropical cyclone Wilma, causing flooding and slips.
Historically they have been worst-hit by such weather patterns, which "pack a powerful punch", said Niwa scientist Mike Revell.
Northland to Gisborne were the most prone areas, and had been struck by some of the most damaging cyclones, including Bola in 1988.
The tropical cyclone season lasts from November to April, so the worst may not be over this year, said Revell.
"We've had four already and we're only halfway through the season."
The figure was well above the average of nine tropical cyclones throughout the whole southwest Pacific in a year.
Other weather was also becoming more extreme.
"The temperatures are going up - the climate has warmed globally in the last century," said Niwa's James Renwick.
The warmer air held more moisture, which meant heavier rainfall was more likely, he said.
The risk of drought between rainfall was also an increasing risk in the next decade because of changing weather patterns.
New Zealand was in an "extreme phase of La Nina", which had contributed to the number of tropical cyclones this year.
