Today might be the second big cold blast of the week but it won’t actually be until Sunday and Monday that the coldest of the air will surge northwards covering all of New Zealand.

Westerly winds today, while colder than recent winds, are still fairly mild over northern New Zealand despite the occasional hail storms.

As warm and cool air continue to mix today expect more big downpours, isolated western thunderstorms and hail showers off an on.

But this weekend a large high finally exiting Australia will change shape from being stretched west to east to instead being pulled north to south. This big shift in shape will then work with a low south east of New Zealand this weekend and early next week to dredge up a truly polar southerly over the country. This air flow will be drier but the temperature will drop. Wellington’s high on Monday is 10 degrees. 

Gisborne has a high in the mid teens today but just 12 degrees by Monday and Tuesday. In fact this southerly that kicks in this weekend won’t fade from eastern New Zealand until Wednesday of next week. It will be early next week when the coldest air hits the South Island too with overnight lows dropping to around -3 to -8 through parts of Otago and through the mountains.

We have good news for many though – the long range forecast once these eastern showers clear next week is for a mainly dry week ahead thanks to this incoming high with the next big rain maker potentially not until the end of the first week of June based on modelling at the moment.

– 7 day rain map from the US Govt indicates a normal to slightly drier than normal week coming next week. Areas in white = average rainfall, red/pink = drier than usual and blue = wetter than usual. Map from today until next Friday.

– WeatherWatch.co.nz