These thunderstorms have the potential to bring rain with intensities of 10-25mm/h and hail 5-15mm in diameter, MetService said.
Heavy rain is forecast for the South Island at the start of the day, MetService said this should clear later in the day. Southerly winds and cooler temperatures are likely to persist.
Southland and Clutha are under a heavy rain watch until noon today.
MetService also said periods of heavy rain may approach warning-criteria levels, especially inland.
South Islanders will also need to keep an eye on the roads. MetService has issued a road snow warning for the Crown Range Rd and the Lindis Pass from 3am to 9am.
🟠❄️Road Snow Warnings issued for the Crown Range Road and the Lindis Pass.
On Monday, there will be showers in the southern parts of the North Island, with northwesterlies rising to gale.
The west of the North Island is expected to be partly cloudy with isolated showers in the west. The rest of the north will be mainly fine.
A front is forecast to move across the South Island on Monday, with a period of heavy rain for western areas.
A front is forecast to move across the South Island, preceded by a period of heavy rain for western areas. Photo / MetService
There is “low confidence” of significant rainfall for Fiordland and the ranges of Westland, as well as the Otago and Canterbury headwaters, MetService said.
Northwest gales are likely in exposed parts from Fiordland to Wairarapa, and they may become severe from Canterbury northwards, MetService said.
On Tuesday, the front is forecast to move across the North Island early, followed by a showery west to southwest flow and easing to isolated showers later.
There is low confidence of west to northwest gales becoming severe in exposed parts of the Wairarapa and Tararua districts and Hawke’s Bay south of Hastings.
In the South Island, there is a possibility of snowfall on Tuesday.
Showers are likely in the west and south, with snow possible to 600 metres in the south.