After consultation with local Regional Councils and Civil Defence the Orange Warnings for Heavy Rain in Westland and Buller have been upgraded to MetService Red Warnings.

The significant rain accumulations will cause disruptions across the regions that saw similar heavy rain events in July 2021 and February 2022.

MetService meteorologist Lewis Ferris says, “An extended period of persistent, heavy rain is likely to cause major disruption around northern and western parts of the South Island. The ranges of Buller and Westland could see 350-600mm of rain over a 56 hour period ending Thursday afternoon/evening. Areas will likely exceed their total average August rainfall during this period.”

The Tasman Ranges could see even larger accumulations of rain and are currently under an Orange Warning but there is still potential for an upgrade to a Red Warning for this area.

“Even if river levels are currently normal, the intensity of rain to come will mean these quickly rise and extreme caution is advised. Delays on the roading network are also to be expected. Closer to the coast the highest risk of flooding comes when the tides are high. Communities are at risk of being isolated,” adds Ferris.

Rainfall rates are forecast to peak on Wednesday, but the rain lingers into Thursday. There is a brief respite on Friday, however rain looks to return by the end of day and bring further rain into the weekend. Keep up with the forecast and follow advice of local authorities.

“While the biggest impacts are expected within the Red Warning area, bear in mind that surrounding regions will also need to be on alert as large amounts of rain falling near the mountain tops can cause rivers to rise in areas not under a Heavy Rain Warning. The rain is accompanied by a warmer than normal airmass which will likely lead to snowmelt which will further increase the water draining into rivers,” cautions Ferris.

Severe Weather Watches and Orange Warnings are also in force for Heavy Rain and Strong Winds around the North Island.

Local state of Emergency for West Coast

Grey District Mayor Tania Gibson, Chair of the West Coast Emergency Management Joint Committee, has signed a Group Declaration for the West Coast region at 1430 today.

The Group declaration is to provide a strategic and coordinated response to the severe weather event impacting the West Coast.

“This has now developed into a significant event for the West Coast. We are expecting impacts to be felt across the region and making this declaration now will assist with surging in additional resources to the region where we need it.”

The upgrade of the MetService forecast from orange to red, as well as forecasted river levels, gales and a swell warning, has the potential to cause flooding, slips and other damage associated with such events and isolating the West Coast from other regions.

“This decision has been made based on the information supplied by the Group and Local Controllers, our emergency service partners and the National Emergency Management Agency.”

“We have already had a considerable number of agencies and additional staff deployed across the region. Everyone is working incredibly hard with planning and preparing.”