Weather: 'High potential' for a second cyclone in South Pacific this week

There's "high potential" for another cyclone to develop this week, just days after ex-tropical Cyclone Uesi wreaked havoc in the South Pacific.

WeatherWatch says the weather event is developing northeast of New Zealand and the Joint Typhoon Warning Centre has issued a Tropical Cyclone Formation Alert.

This particular system could be a tropical cyclone until the end of the week.

"At this stage, for land, it will be a rainmaker for the most part based on most modelling," WeatherWatch says.

"This storm will be the second one within days of Cyclone Uesi but is not currently forecast to hit New Zealand."

It will get closest to New Zealand on Thursday when the storm runs into high pressure.

"Swells and waves at our easternmost beaches will be affected with wave heights and easterly swells around East Cape and Gisborne likely increase by up to 1 metre," WeatherWatch says.

There were concerns about ex-tropical Cyclone Uesi wreaking havoc on the West Coast of New Zealand overnight.

While there was some heavy rain and strong wind, it was "nothing out of the ordinary", Richard Green, a weather commentator, told Radio New Zealand's First Up programme.