Wairarapa is in for a wet remainder of summer, while another cyclone could be on the way.
National Institute for Water and Atmospheric Research [Niwa] said in its seasonal climate outlook, released on Friday, that heavy rainfall and possible flooding for the North Island and northern South Island was likely in the coming weeks and months.
It said sub-tropical air masses, in conjunction with marine heatwave conditions, could elevate overnight temperatures and humidity.
Temperatures are about equally likely to be near average or above average for the next three months.
“More frequent onshore winds and above average coastal sea surface temperatures may lead to higher humidity levels, more cloud cover, and warmer overnight temperatures. Fewer northwesterly winds will likely continue to limit the number of days above 25°degrees Celsius,” Niwa said.
However, Wairarapa is not in for a break from the rain, while rainfall totals are most likely to be above normal.
Sub-tropical low-pressure systems and atmospheric rivers were forecast to occasionally impact the region, increasing the risk for heavy rainfall and flooding, Niwa said.
Additionally, soil moisture levels and river flows are most likely to be above normal.
Metservice has warned that a tropical low over the Coral Sea was likely to develop into a Tropical Cyclone in the coming days, hitting New Zealand from the north on the weekend.
“If this system does pass close to the North Island, it will be another significant weather event potentially affecting vulnerable areas which are still recovering from recent severe weather.”
Metservice said current predictions would see winds picking up about northern parts of the North Island during the weekend, while there was low confidence of severe easterly gales affecting Northland on Sunday.
It said eastern coasts would see the largest drop in temperatures over the next week.
“Temperatures are forecast to remain below or around average through to Sunday as a ridge of high pressure builds in from the west on Thursday, keeping the temperature airmass around.”
Metservice said it was important to emphasise that the cyclone’s path was still uncertain because the system has not full developed yet.
“We will have a much better idea about the path this system will take, and any related severe weather, in another couple of days once it has formed.”
