MetService Severe Weather Warning Issued at 8:09pm Wed 6 May 2026 Heavy rain for the north and west of the South Island A low and associated front are expected to move eastwards over the South Island during Thursday, bringing heavy rain to western and northern parts of the Island. Note, another active low pressure system follows, and is expected to move over the South Island during Friday and Saturday, bringing more heavy rain and possibly severe gales. Please keep up to date with forecasts as more Warnings and Watches will likely be issued in the coming days. Heavy Rain Warning - Orange Area: Tasman District northwest of Motueka Period: 31 hours from 12:00pm Thu 7 May to 7:00pm Fri 8 May Forecast: Expect 250 to 350 mm of rain, but possibly as much as 400 mm about the ranges. Peaks rates of 20 to 30 mm/h expected during Friday with thunderstorms possible. Low chance of upgrading to a Red Warning. Impact: Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions possible. Action: Clear your drains and gutters to prepare for heavy rain. Avoid low-lying areas and drive cautiously. Area: Buller District Period: 33 hours from 10:00am Thu 7 May to 7:00pm Fri 8 May Forecast: Expect 200 to 300 mm of rain about the ranges, and lesser amounts near the coast. Peak rates of 15 to 25 mm/h expected during Friday with thunderstorms possible. Low chance of upgrading to a Red Warning. Impact: Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions possible. Action: Clear your drains and gutters to prepare for heavy rain. Avoid low-lying areas and drive cautiously. Area: Westland District Period: 23 hours from 8:00pm Wed 6 May to 7:00pm Thu 7 May Forecast: Expect 200 to 300 mm of rain about the ranges, and lesser amounts near the coast. The largest accumulations are likely about and south of the glaciers, where some models indicate 350 mm is possible about the ranges. Peak rates of 25 to 35 mm/h expected during Thursday with thunderstorms possible. Note, another period of heavy rain is expected from Friday afternoon. Low chance of upgrading to a Red Warning. Impact: Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions possible. Action: Clear your drains and gutters to prepare for heavy rain. Avoid low-lying areas and drive cautiously. Area: Fiordland north of Doubtful Sound Period: 15 hours from 8:00pm Wed 6 May to 11:00am Thu 7 May Forecast: Expect a further 100 to 140 mm of rain on top of what has already fallen, especially north of George Sound. Peak rates of 15 to 25 mm/h expected Thursday morning with thunderstorms possible. Note, another period of heavy rain is expected from Friday afternoon. Minimal chance of upgrading to a Red Warning. Impact: Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions possible. Action: Clear your drains and gutters to prepare for heavy rain. Avoid low-lying areas and drive cautiously. Area: Headwaters of the Canterbury lakes and rivers about and south of Arthur's Pass Period: 18 hours from 12:00am Thu 7 May to 6:00pm Thu 7 May Forecast: Expect 120 to 180mm near the Divide, with 80 to 120mm within 15km east of the divide. Peak rates of 20 to 30mm in possible thunderstorms Thursday afternoon. Freezing level about 3000 metres. Note, another period of heavy rain is expected from Friday afternoon. Minimal chance of upgrading to a Red Warning. Impact: Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions possible. Action: Clear your drains and gutters to prepare for heavy rain. Avoid low-lying areas and drive cautiously. Area: Headwaters of the Otago lakes and rivers Period: 15 hours from 8:00pm Wed 6 May to 11:00am Thu 7 May Forecast: Expect 100 to 150mm to accumulate near the divide, with 70 to 100mm within 15 km east of the divide. Peak rates 20 to 30mm per hour in possible thunderstorms during Thursday morning. Freezing level about 3000 metres. Note, another period of heavy rain is expected from Friday afternoon. Minimal chance of upgrading to a Red Warning. Impact: Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions possible. Action: Clear your drains and gutters to prepare for heavy rain. Avoid low-lying areas and drive cautiously. An update will be issued by 10:00am Thu 7 May © Copyright Meteorological Service of New Zealand Ltd 2026 Reproduction of this content is permissible and encouraged but requires an attribution to MetService, and such content cannot be modified or edited without the prior approval of MetService. Action advice supplied by the National Emergency Management Agency. This forecast is available on the MetService website at: https://www.metservice.com/warnings/home Definitions for MetService warning criteria are available at: https://www.metservice.com/warnings/home#weather-criteria Please do not reply to this e-mail. Mail sent to this address cannot be answered.
