The Joint Typhoon Warning Center – the global organisation that monitors and forecasts all tropical storms – late this morning declared Gita fully “extra-tropical” at latitude 35.5S. But Gita this afternoon remains a storm with winds equal to a category 2 tropical cyclone as it churns towards central New Zealand.

The core of the storm has turned cold and the rain has shifted to the southern half of the cyclone – this is dramatically altering the look of the storm on satellite maps, it no longer has that perfect cyclone look and once it reaches New Zealand it will lose it’s perfect circular shape at the centre too – as it morphs into two low pressure systems and the energy is spread out over a much larger area.

Gita actually picked up strength a little this morning, winds averaging 93km/h lifted to just over 100km/h. However before it reaches New Zealand it will likely weaken a small amount – maybe around 20km/h with the sustained winds – making it equivalent to a strong category 1 tropical cyclone. This makes it damaging still with flooding rains (with tropical origins so rain will be torrential at times), dangerous seas and destructive winds. New Zealand’s terrains will push the wind gusts right up, potentially to 150km/h+ in exposed ranges/hill tops/wind tunnels etc.

Significant rain has already fallen in some parts of the upper South Island with over 50mm and the storm is still hours away from bringing the torrential areas of rain.

Landfall of Cyclone Gita still looks likely to be this evening – anytime from 6pm to 10pm and still the north western corner of the South Island/Cook Strait area looks most likely to be hit – this may still change a little, we’ll keep you posted if we see any big changes.

Significant storm surge is still expected from Westport to as far north as Waikato and even Auckland on the western coastline. 

The worst winds appear to be tracking between about Hokitika/Christchurch to New Plymouth/ Wellington but gales will likely extend beyond that, as far north as Auckland and as far south as even Fiordland through the mountains.

Because Gita has lost that warm core and “tropical” cyclone status the middle is changing already and the rain bands in the southern half of it will continue to extend and grow this afternoon and evening. Rainfall totals look significant in the South Island, in particular from about North Otago northwards.

This stretching out action of the centre of the cyclone, now that it’s extra-tropical, means the winds at the centre will expand and so once Gita makes landfall there could be areas of calm through Central New Zealand amongst the pockets of damaging winds. The Southern Alps and ranges of the lower North Island, plus Cook Strait, all work to make this a very complicated forecast to work out and communicate precisely – there are many moving parts which will be continuously changing once Gita makes landfall.

The storm is also picking up speed and the centre is now travelling SW at 28 knots (52km/h) as it comes towards New Zealand.

By noon Wednesday the worst will be over but more rain will be falling across the South Island which could be an issue if some areas are flooding.

If you’re still confused about what extra-tropical means, click here for more details via Wikipedia.

ABOVE and BELOW 6PM TUESDAY

BELOW: 6pm Tuesday wind gust map

BELOW: Midnight wind gust map.

– Maps ECMWF

– WeatherWatch.co.nz