Weather: 'Sizable cyclone' could brush New Zealand by end of week

There's trouble brewing in the Pacific with warnings another cyclone could be forming near Fiji - and it could churn up "deadly" seas around New Zealand.

"We're watching for the potential development of a tropical cyclone near Fiji later in the week!" NIWA says. "The next name on the list is Tino."

WeatherWatch says Fiji is currently forecast to be in the path of the possible storm.

"GFS modelling and ECMWF both paint a similar picture of the tropical storm crossing directly over Fiji this Thursday and Friday," it says.

"It could bring heavy rain, slips and some flooding along with winds strong enough to cause some damage."

Tonga may also be impacted on Friday as the storm churns by to the west. 

"Both GFS and EMCWF show the storm being well to the west of Tonga but bringing a surge of heavy rain, strong to gale-force winds and rough seas," WeatherWatch warns.

New Zealand in the firing line?

WeatherWatch says the offshore storm may get close this upcoming weekend, and by next Monday a "very deep and sizeable storm" should lie east of the North Island.

High-pressure over New Zealand should be enough - for now - to push the storm away and protect us from any direct hit.

"The likely tropical storm is forecast to track close enough to influence our weather, but hopefully far enough offshore to not bring any severe weather," it says.

WeatherWatch warns that this will still be close enough to bring stronger winds and bigger swells from the east.

"Remember this storm will bring more dangerous beach conditions to the east from Northland to Coromandel, Bay of Plenty to East Cape, Gisborne and down to Hawke's Bay and maybe even Wairarapa," it says.

"Offshore storms can be deadly in summer in NZ when the weather on-land is calm. There are a number of incidents in recent years - some leading to drownings, others leading to near-drownings - when offshore storms like this churn up stronger rips and bigger waves at our most populated eastern beaches."