“The tropics are likely to get more active and that may include a tropical cyclone that forms in the north,” Brandolino said.
“If that sets up over your neck of the woods then that can change the complexion of what the season looks like in terms of rainfall.”
He said while there could be a normal amount of rain over the next three months, it would come in the form of “decent drops” followed by dry periods.
Winds are expected to be stronger than usual over autumn and there will be more frequent north-west winds.
Brandolino said it was important for the public to remember that the climate outlook was more of a theme than a specific forecast.
What to expect in Whanganui this week
Whanganui’s weather week begins with a heavy rain watch, possible thunderstorms, and a strong wind watch on Monday.
Metservice meteorologist Juliane Bertbolt said an intense trough was making its way up the country - bringing strong northwesterly winds and heavy rainfall.
“Northwest winds may approach severe gale in exposed places and we advise caution for people riding motorcycles or driving high-sided vehicles,” Bertbolt said.
“The wind and rain are expected to ease off towards evening but it will be a good idea for people to secure things like trampolines and outdoor furniture the night before.”
A high of 24C is expected followed by an overnight low of 12C.
The outlook for Tuesday is better, with a few showers clearing in the evening but remaining partly cloudy.
“There will be a noticeable temperature drop on Tuesday as fresh westerly conditions move in behind that front,” she said.
A high of 19C is forecast followed by an overnight low of 11C.
“Once that trough has passed things will be warmer and more settled due to a high building over the Tasman.
“There will still be a few showers and light winds during the last days of the week but things will be fine and settled by the weekend.”
A high of 21C is forecast for Wednesday followed by an overnight low of 11C and similar conditions are expected on Thursday, with a high of 22C and overnight low of 13C.
Friday’s high is expected to reach 24C with a low of 13C and some showers.
The clouds and rain will be gone by Saturday, when a few light southerly winds are expected along with a high of 24C followed by an overnight low of 12C.
Eva de Jong is a reporter for the Whanganui Chronicle covering health stories and general news. She began as a reporter in 2023.
