A front moves slowly northeastwards over the South Island on Tuesday, before weakening as it moves across the North Island on Wednesday. This front is preceded by a period of northerly rain and followed by a west to southwest flow across the country through to Friday.

There is moderate confidence of warning amounts of northerly rain in Fiordland and south Westland early Tuesday morning, and for the remainder of Westland later on Tuesday.

The westerly flow is expected to strengthen in the far south on Friday. There is low confidence of westerlies becoming severe about coastal Clutha and Southland including Stewart Island on Friday as depicted on the chart.