Meteorologists at MetService have extended their severe weather outlook to include more North Island regions.

The government owned forecaster is monitoring the same low WeatherWatch.co.nz reported on Friday afternoon.

WeatherWatch.co.nz says this new sub-tropical low is more likely to bring heavy rain to northern and north eastern regions than ex-tropical cyclones Zelia and Vania, which tracked to the west of the upper North Island.

This new sub-tropical low is growing in strength – unlike Zelia and Vania which were both disintegrating – and is also tracking in a different direction that will push the heaviest rain into northern and north eastern parts of the North Island.

WeatherWatch.co.nz head weather analyst Philip Duncan told NewstalkZB’s Danny Watson on Friday afternoon that this weekend’s weather could be more “La Nina” if it tried. 

“This is absolutely text book La Nina weather.  We have a rain bearing sub-tropical low pushing into northern New Zealand tracking down the east coast with increasing humidity behind it.  Further south we have strong east to south east winds over the lower North Island and in the South Island we have cool easterlies, low cloud and drizzle for the east coast and sunny, warm, weather for the West Coast this weekend”.

MetService forecaster Gerard Barrow says rain should become persistent and heavier about Gisborne and the Coromandel Peninsula from Saturday evening.

“The Heavy Rain Watch for these areas has now been upgraded to a Warning” he says. 

The heavy rain warning, issued Friday night, is for the ranges of Gisborne north of Tolaga Bay and the Coromandel Peninsula where rain is expected to become heavy Saturday evening, and from 9pm Saturday to midday Sunday 80-140mm could accumulate.

Further significant heavy rain is likely to accumulate after midday Sunday and into Monday.  

“Overnight Saturday the trough and rain should intensify further. The intensification of the trough and rain is associated with a subtropical low which is expected to move southwards towards the country during Sunday” says Mr Barrow.

He says for Northland, Bay of Plenty/Rotorua and Hawkes Bay, there is also the potential of significant amounts of heavy rain accumulating in these regions overnight Saturday and during Sunday.  “At the moment there is still uncertainty with the precise track and speed of movement of the low, (and consequently how much rain will accumulate in specific areas), and it is very likely that several more regions in the North Island may have to be included in future warnings or watches”

For the latest warnings click here

WeatherWatch.co.nz will have extra updates across the weekend covering this significant rain event for the North Island.

Graphic / MetService