Heavy rain, snow warnings

low from the north

Hill country farmers inland from Gisborne are advised to look to their stock with heavy rain and snow warnings issued today for a large part of central North Island high country.

MetService issued the first snow watch yesterday evening as a warm, moisture-laden sub-tropical low barrelled down towards the North Island, while a cold airstream blasted up from the deep south, heading for a collision over the top half of the island.

This has intensified and the warnings for the Gisborne region were this morning upgraded to orange status for the 15 hours from 3pm this afternoon to 6am tomorrow morning.

The watch covers the high country of Gisborne, Hawke's Bay and Taupo, from Matawai to the Kaimanawa and Kaweka Forest Parks.

For the Gisborne ranges, MetService says to expect one to 20 centimetres of snow above 800 metres, with lesser amounts down to 600 metres.

Periods of heavy rain are forecast from this afternoon through to tomorrow morning.

MetService says to expect 80 to 120 millimetres of rain, with the largest amounts north of Gisborne.

Peak rates of 10 to 20mm an hour are expected overnight.

Temperatures are forecast to plummet, with the freezing level down to 1200 metres overnight.

Gisborne's air temperature is forecast to be down to just 1 degree at 6am on Wednesday.

With lambing under way, the snow watch is bad news for high country sheep farmers and a setback for spring grass growth.

On top of the rain and snow, MetService also has a strong wind watch in place for north of Ruatoria and the eastern Bay of Plenty, and says south to southeast winds may reach severe gale level in exposed places.

This latest weather hit is another blow to the region, with climate maps from the National Atmospheric and Water Research Institute (Niwa) showing the Gisborne flats starting to dry out.

However, the rest of the district is still wet — just 10mm off capacity in soil moisture.

For the past 15 days temperatures have been warmer than usual, running at 1 to 2 degrees above average of the region.

Niwa's latest three-month outlook through to the end of November expects temperatures to remain above average, with rainfall near normal.

Niwa warns more sub-tropical lows could track towards the region, increasing the risk for heavy rain.

The forecast suggests more northeasterly winds may lead to higher humidity, more cloud cover and warmer nights.

Meanwhile, MetService's September outlook says a more normal spring-time pattern “could emerge in the last week of the month as high pressure slides east of the country”.