A northerly airflow increases on Tuesday ahead of a deep intense low which moves over the South Island later in the day.

Sunny spells and thickening high cloud for the upper North Island, overnight rain. North to northeasterly winds freshen. Sunny areas and thickening high cloud for the lower western North Island, rain develops overnight becoming heavy for Taranaki. Freshening northwesterly winds rising to gale about coastal parts later in the evening or overnight.

Sunny areas and increasing high cloud along the east coast, north to northeasterly winds freshen from afternoon. Mostly cloudy for Wellington with rain overnight, gusty north to northwesterly winds rising to gale in the evening.

Sunny areas and thickening high cloud for Nelson and Marlborough, rain develops in the evening or overnight. Strengthening north to northwesterly winds from afternoon rising to gale in the evening. Thickening high cloud for Canterbury, a few showers late evening / overnight with heavy rain in the high country. Increasing north to northeasterly winds, strong to gale about Banks Peninsula northwards later in the evening.

Mostly cloudy along the West Coast, showers about South Westland turning to rain in the afternoon then spreading northwards. Rain heavy by evening for all with torrential falls possible then easing overnight as gusty northerlies change strong west to southwest. Sunny areas and increasing high cloud about Southland and Otago, rain develops in the evening, possibly heavy for a time then easing overnight as northerlies change gusty southwest.