A period of strong winds and heavy rain is about to begin with MetService today issuing several rain warnings for the South Island.   

A deluge of up to 280mm of rain is predicted to accumulate in the 27 hour starting 3am Tuesday across the western South Island ranges – and spill over into some east coast rivers.

WeatherWatch.co.nz says that on today’s satellite map images large showers, some most likely containing hail and thunderstorms, are now appearing around Tasmania and will reach the South Island’s west coast tomorrow night.

It’s possible some squalls may contain small tornadoes in exposed west coast regions as far north as Taranaki.

Head weather analyst Philip Duncan says it’s not just the rain we should be looking out for.  “It’s going to be a windy ol’ week ahead with gales about eastern areas from Cantebury to southern Hawkes Bay, especially inland areas east of any main ranges”.

Mr Duncan says the stormy weather will arrive tomorrow along the West Coast then spread into the North Island overnight and into Wednesday morning. 

“With a large high to the north and a deep low to the south New Zealand will lie smack bang in the middle of the squeeze zone – the area half way between these two systems where the winds are at their strongest.  The windy weather should last the entire week and into the weekend”.

The wind direction means northern and eastern parts of New Zealand should have a mild week with no frosts predicted anywhere by WeatherWatch.co.nz for the next 6 days.

While the current rain warnings are mainly for rural areas the heavy rain is likely to affect river levels along the east coast – and coupled with snow melt it may cause flooding in some areas.  South Island farmers are advised to be aware of the heavy rain forecast to move in to the area.

See all the current warnings here.