Weather forecasters say worst of electrical storms over but heavy snow likely in south.

Thunderstorms are expected to batter the lower North Island and upper South Island, farmers near the Manawatu River are being warned to move stock because of flooding fears and survival kits might be needed in Southland.

Snow is causing havoc on the South Island's roads as wild weather continues to batter the country and while the storm is now peaking over the country, some places should brace for another rough 48 hours.

Thunderstorms are set to strike the southwest of the North Island this morning, with tornadoes possible, as one of the biggest storms of the year lashes the country.

The ash cloud from Chile's Mt Puyehue Cordon Caulle volcano has returned to cause more disruption to flights.

A bitterly cold southerly from the Antarctic will sweep up the country this week, bringing snow to all skifields.

A tornado, floods and king tides wreaked havoc across the country yesterday.

Severe gales and heavy downpours chased by bitter-cold southerly winds are expected this weekend.

Air NZ would adjust flight routes and altitudes to ensure aircraft remained clear of ash.

International flights have been cancelled as a volcanic ash cloud from Chile heads towards NZ,

Only the skifields will welcome the weather this weekend as frosty winter temperatures are expected to finally kick in.

As NZ skifields delay opening because of unseasonably warm weather, some Aussie resorts are blanketed...