A strong northwesterly airflow lies over New Zealand today, within this flow a front moves northwards over the South Island during the day reaching the lower North Island overnight. This front continues over the North Island on Tuesday meanwhile a southerly change affects the lower and eastern South Island. A slack pressure gradient on Wednesday could mean unstable conditions for some.

Blue – Heavy rain and thunderstorms pushes northwards along the West Coast of the South Island today, easing from the south afternoon onwards. Heavy rain moves into Taranaki later this evening / overnight.

Purple – Northwesterlies will be strong to gale about inland Canterbury and through Cook Strait, easing about Canterbury from later this afternoon. Winds pick up about western parts of the North Island overnight.

Yellow – Temperatures will crack the 20 degree mark for many eastern regions today however the eastern North Island may see high’s in the mid to late 20’s.

Blue – Morning heavy rain about Tasman / Nelson and Marlborough eases. Further north may see heavy falls as a front passes over the North Island during the day.

Southland and perhaps parts of Otago sees heavy showers in the afternoon as a southwest change moves through, easing in the evening. And there is a chance a southerly flick may bring a few heavy isolated showers to coastal Canterbury mid afternoon then easing by evening.

Purple – Expect brisk to strong northwesterlies for many North Island regions during Tuesday, easing from afternoon after a frontal zone moves through. Winds gust to gale especially through Cook Strait and other coastal areas.