This week begins with a broad area of low pressure dominating the weather, but there will be a brief respite on Tuesday as a ridge moves over the country.
However, a new low pressure centre has its eyes on the country towards the end of the week.
For the North Island, an active front crosses this evening, followed by an unstable west to northwest flow, with thunderstorms and hail likely in the west. The flow turns strong, cool southwest Monday afternoon, and the risk of thunderstorms becomes confined to the north of the island.
On Tuesday, most of the showers clear to fine weather as a ridge crosses the country. From Wednesday evening, a new front crosses the North Island, bringing a period of rain for most places, followed by showery westerlies. A new low pressure area moves over the island on Thursday, maintaining rain or showers in the south and west.
On Friday, the entire North Island lies in a cool southerly flow, resulting in fine weather in the north, but showery conditions south of the volcanic plateau.
Looking to the South Island, low pressure lies to the east of the island today and on Monday. A front brings rain to the south of the island today and showers in the west, with possible thunderstorms and snow down to 800 metres in the south.
Places west of the Divide, as well as Nelson, become fine on Monday, but southerlies, low cloud and rain set in elsewhere over the island, and snow is also possible about some higher roads and passes. On Tuesday, the ridge brings a clearance to mainly fine weather, while Wednesday sees a front bringing rain to places west of the Divide. This front moves east of the Divide on Thursday, with periods of rain and strong, cool southerlies from about North Otago northwards.
The week ends with easing southwesterlies over the South Island, with any remaining showers clearing.
MetService meteorologist Andy Best says the changeable nature of spring weather means people should always be aware of any Severe Weather Watches and Warnings, especially if travelling.
“All the latest Severe Weather forecasts are to be found on the MetService website and on the MetService app, together with thunderstorm forecast diagrams and severe weather outlooks.”