The deadly storm that has been hammering Sydney and parts of New South Wales continues into day three today – held up due to high pressure over New Zealand.

“The high pressure system over New Zealand is acting like an invisible wall out over the Tasman Sea, holding this low in place near Sydney and bringing day after day of torrential downpours, huge seas and damaging winds” says head weather analyst Philip Duncan.

Fog and smog over parts of New Zealand today is caused by the calm conditions under the high.

The high over New Zealand is already starting to move further east of the country – and like gridlocked traffic the low near eastern Australia will start to follow slowly behind it.

“By Friday the low just off Sydney’s coastline will weaken significantly – as mostly dry weather remains over New Zealand, however with the high drifting further away to our east a northerly quarter wind flow will develop over the country” says Duncan.

This means a warm weekend for many regions with winds from the north west to north east for many regions – the air flow out of the warmer subtropics too.

By Sunday the leftovers of the Australian storm will be reforming over the southern Tasman Sea – thanks to a shot of energy out of the Southern Ocean.

A new, larger, low will deepen rapidly on Sunday PM and into Monday AM – just as it starts to cross New Zealand.  

“Some parts of New Zealand will have a wet and windy public holiday on Monday – with the low affecting most of the country at some point across the day”.

“Like New South Wales the low will take a few days to clear New Zealand – however it will be a different low by the time it reaches New Zealand with any potential severe weather coming in different forms” says Duncan.

There is a chance of isolated thunderstorms across Monday and Tuesday. Heavy rain is also possible in western areas.  Strong to gale force north to north west winds are also possible in some areas.  But it’s too far out to lock in any potential severe weather risks with any detail.

Mild weather is expected across most of New Zealand on Monday and Tuesday, with a colder change moving in later on Tuesday and into Wednesday.

A repeat of the major damage in parts of New South Wales is not expected in New Zealand – however the low will have enough energy to create localised damaging weather in some parts of our country.

WeatherWatch.co.nz will continue to monitor it closely via our news and video updates this week.

– WeatherWatch.co.nz