MetService issued orange-level heavy rain warnings for parts of New Zealand's South Island starting Sunday [4].
The warnings come as a significant autumnal change brings wetter and windier weather to the region, increasing the risk of dangerous flooding and slips.
The warnings cover the Westland, Buller, and Tasman districts, as well as the ranges between Nelson and Marlborough on the South Island’s West Coast [1, 2]. Forecasters expect heavy downpours as part of the shifting weather pattern [1, 3].
Some areas of the West Coast may receive up to 250 millimetres of rain [1]. The weather system is expected to last through the weekend [1, 3].
Infrastructure has already been affected by the volatile conditions. Two state highways were closed due to flooding [2]. Specifically, the segment of State Highway 6 from Rai Valley to Havelock was shut [2].
MetService, the national weather agency, continues to monitor the situation as the system moves through the region [1]. Residents in the affected districts are advised to remain cautious of potential landslides and rising water levels.
“Up to 250 millimetres of rain may fall on parts of the West Coast”
The issuance of orange-level warnings indicates a high potential for significant impact, where the volume of rain can quickly overwhelm local drainage and destabilize slopes. The closure of State Highway 6 highlights the vulnerability of the region's transport corridors during extreme autumnal weather events, potentially isolating rural communities.
