Huge rain event forecast for the West Coast

May 9, 2016

There’s going to be some huge rainfall amounts for the west of the South Island this week. Several weather fronts will be hitting the region over a period of a few days, which means that the prolonged period of rain could generate a massive total of 400 to 500 mm in some places by the weekend, especially about the Southern Western Ranges. The first place to be hit will be Fiordland, where a heavy rain warning is already in place for heavy rain from Monday night.

The heavy rain then kicks in for Westland and Buller on Tuesday night, with the heaviest falls expected around the ranges. We are also forecasting heavy rain for the headwaters of the Otago and Canterbury lakes and rivers south of Arthur’s Pass from Tuesday evening. “Heavy rain over such a long period is likely to cause some rivers to rise rapidly and make conditions difficult for trampers,” said meteorologist Emma Blades.  

This series of fronts will also bring rain to western parts of the North Island mid-week, which will be very welcome for farmers after a relatively dry autumn. Unfortunately these fronts will also generate northwest gales for parts of the South Island, reaching the lower North Island on Wednesday. “Wellington is very likely to experience northwest gales from mid-week, and although strong wind events aren’t unusual for the Capital, it’s worth keeping an eye on the forecast and taking any necessary precautions in relation to keeping safe on the road and securing loose items around your property,” commented Ms Blades.

The same weather system will also be bringing large swell to western shores on Thursday and Friday. “Due to the prolonged westerly flow, combined with strong winds, we are expecting to see large waves hitting our western beaches from Thursday,” added Ms Blades.

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MetService issues Warnings, Watches and Outlooks for severe weather over New Zealand. 

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