Wall of storms on the way

Strong winds blew this yacht onto St Heliers beach this morning. It was safely pulled off by the police rescue boat. Photo / Kishanda Blamey

Brace yourself - a wall of thunderstorms the length of New Zealand is about to hit, bringing heavy rain, thunderstorms, strong winds and even snow.

The storms, which were expected to arrive this morning, are moving towards the country in front of a large low pressure system that was engulfing much of the Tasman Sea last night.

WeatherWatch head weather analyst Philip Duncan said the thunderstorms would probably break up before they hit land and become more isolated.

Areas most affected would be the west coasts of the North and South Islands. Western areas of the North Island would have heavy rain.

Winds would be severe in exposed places but most populated areas should be spared, Mr Duncan said.

Snow was likely later in the week, in Canterbury, Southland, Otago and Banks Peninsula when the low moved on to the country.

MetService Weather Ambassador Bob McDavitt said most of the bad weather would have passed by midnight tonight but the low would mean some "showery days" and unsettled weather for most of the week.