A westerly airflow lies over the North Island today while a northwesterly airflow lies over the South Island, a front in the Tasman Sea starts to make its presence felt about the southwestern corner of the South Island from afternoon. A front pushes northwards over the South Island on Friday reaching the North Island later in the evening or overnight. Cool southwesterlies for much of the country on Saturday.

Thursday

Blue – Some heavy rain moves into Fiordland / South Westland from evening.

Friday

Blue – Heavy rain moves northwards along the West Coast of the South Island during the day, weakening as this band of rain moves onto the western North Island later in the evening. Some heavy rain may also affect Southland for a time in the morning then easing from afternoon.

Purple – Strong northwesterly winds develop through Cook Strait in the afternoon, winds may gust to gale at times then easing later in the evening as winds change gusty Southerly.

Southwesterlies about coastal Canterbury may be brisk / strong for a time from mid afternoon then easing overnight.

Saturday

Blue – Afternoon convergence combined with cold air aloft brings the risk of heavy showers after midday for the inland Nelson / Marlborough area. There is the low chance of a thunderstorm here also.