A front slowly moves northwards over the South Island today reaching the lower North Island late afternoon / evening within a strong northwesterly airflow. A low forms in the Tasman on Saturday then combined with the front mentioned above moves over the North Island from afternoon. This low passes out to the east of the North Island on Sunday while a ridge lies over the South Island.

Friday

Blue – Heavy rain for the West Coast of the South Island during the day, gradually easing from the south after midday, not easing about Buller till overnight. Also late evening / overnight there may be a rouge thunderstorm about South Westland. Some rain moves onto the lower North Island in the west late afternoon / evening with the chance of a heavy fall.

Purple – A strong northerly airflow covers much of the South Island and lower North Island in the morning but this flow becomes more intense during the afternoon as winds tend strong northwest. Winds may gust to gale from the northwest from midday onwards about the likes of Canterbury and Marlborough, especially inland, and also the Cook Strait area.

Blue – A front passes over the North Island from afternoon bringing a few heavy falls. A chance of thunderstorms about Northland and Auckland as this front moves through.

Purple – Northerlies about coastal northeastern parts of the North Island increase during the morning, gusty / strong during the afternoon then easing in the evening.

Blue – Morning rain about Hawkes Bay and Gisborne may be heavy then easing by midday.