Weather: Maps show thunderstorms, heavy rain, gales threatening next week

Kiwis are being warned to make the most of this weekend outdoors, with heavy rain, severe gales and the risk of thunderstorms arriving next week.

"On Monday, a deepening complex low will approach New Zealand from the Tasman Sea. The low should cross the upper South Island on Tuesday. This low is preceded by strong moist north to northwest winds, and followed by strong cold southwesterlies," MetService warns.

"Much of the country is likely to be affected during this unsettled period stretching through Monday, Tuesday and Wednesday."

This is likely to trigger a moderate risk of thunderstorm activity in North Otago and parts of eastern Canterbury from Monday afternoon, MetService warns.

There is also a moderate risk of thunderstorms in Northland, the far north of Auckland and for Great Barrier Island at the same time.

A MetService graphic shows the winds intensifying next week.

"As we think about the effects on our weather for the first half of next week, it's sobering to take a look at this representation of the forecast winds on Tuesday over Aotearoa," it warns.