Northwesterlies strengthen over New Zealand on Wednesday especially over the South Island from afternoon with a very deep low forming in the southern Tasman Sea then moving past the lower South Island overnight.

For the upper North Island expect mainly sunny weather with some increasing high cloud, winds from the west and afternoon temperatures in the mid to late 20’s. Cloudy in the west for the lower North Island, perhaps even the odd patchy shower about, mainly sunny with high cloud developing for the east coast. Northwesterly winds becoming strong overnight with gales about Cook Strait / Wellington.

Cloudy for the West Coast of the South Island with rain, heavy by midday with torrential falls and thunderstorms by evening. This rain will likely spread into the Canterbury High Country. Thick high cloud for the rest of the east coast with some rain spreading into South Canterbury at times, perhaps a spot or two further north otherwise mainly dry. Northwesterly winds strengthen for all from afternoon with gales possible especially in the east with severe gales developing about inland Canterbury.

Southland and Otago see cloudy skies, it may be dry in the morning then rain moves in during the afternoon possibly heavy for a time evening onwards. Rain may be heaviest in the evening inland where thunderstorms are possible too. North to northeasterly winds freshen from afternoon then overnight winds change gale to severe gale northwest.

Not all regions and towns have been mentioned above. For specific 10 day information for your city, town, rural community or island please see the 1500 forecasts on our homepage!

– Aaron Wilkinson, WeatherWatch.co.nz