Weather: Second cyclone forming, battered East Coast faces 28-hour sub-tropical deluge

Just days after ex-tropical cyclone Hale left a trail of destruction, forecasters are keeping a close watch on a second cyclone that might form near Vanuatu this week.

And a separate low-pressure system is forecast to bring more heavy rain to the ravaged East Coast on Wednesday - a 28-hour-long deluge while the region remains in a state of emergency.

MetService says a sub-tropical low is forecast to approach the North Island on Wednesday and to lie just north of East Cape on Thursday.

“There is currently a tropical low (TD05F) in the Coral Sea to the west of Vanuatu and MetService is forecasting favourable conditions for tropical cyclone development during Wednesday and Thursday,” the national weather authority said.

“Should a tropical cyclone eventuate, it would be the second of the tropical cyclone season (November – April) following Hale. "

This system was expected to track to the southeast affecting southern Vanuatu and was not forecast to affect New Zealand this week, MetService said.

However, meteorologists were keeping a close eye on the situation as it develops and would have a better idea of future tracks once the system has formed.

This morning a heavy rain watch was issued for the entire East Coast from Wednesday morning and will last 28 hours.

The forecaster said parts of Tairāwhiti would potentially get around 80-100mm of rain in a 24-hour period and saturated areas would see impacts faster.

“Rainfall amounts may approach warning criteria, especially north of Tolaga Bay,” said MetService.

Keep an eye on this forecast as there's potential it will be upgraded to a Warning.

Parts of Tairāwhiti will potentially get around 80-100mm of rain in a 24hr period. Saturated areas will see impacts faster.https://t.co/qHyE5zzql5 pic.twitter.com/dxZiiNIZhJ

— MetService (@MetService) January 15, 2023

MetService said along with the rain there would be strong winds in northeastern parts of the North Island.

Gisborne Mayor Rehette Stoltz said officials were keeping a close eye on the MetService advice.

“If we need to close roads or evacuate communities, we will communicate that early with our residents.

“We are keeping our community informed and our team is actively inspecting our roading network and infrastructure to gauge the damage.

“Our community is still in Civil Defence response mode, and we encourage them to listen to any Civil Defence advice via our Facebook page or the media in order for them to stay safe if we have to deal with more heavy rain later in the week.”

Two days ago, badly damaged State Highway 35 was opened to motorists from 7am to 7pm each day, with speed restrictions in place.

However, many towns remain cut off, with 19 roads still closed and a further 29 only open to four-wheel drive vehicles.

Civil Defence officials had urged people to not go swimming, boating or fishing until further notice.

MetService forecaster Mark Todd told Newstalk ZB a moist easterly flow was heading over the country today.

“Northland, down through northern Auckland, Coromandel Peninsula and also Gisborne, we’re expecting it to be somewhat cloudier and possibly a few more showers as well.”

Todd said a sub-tropical low would start approaching the north of the North Island around Wednesday.

“We should expect to see winds freshen up in those areas, and also some rain setting into northern and eastern areas of the North Island.

“Unfortunately it does at this stage look as if there is a risk of some heavy falls for Gisborne and possibly even northern Hawke’s Bay which is really not what we want to be seeing after recent events there.”