KEY POINTS:
A storm is expected to batter most of New Zealand during the next few days.
The MetService said tonight meteorologists were watching a low east of Tasmania which they expected to develop into a potentially vigorous winter storm.
The low should cross the South Island tonight and lie near the Chatham islands for a few days after that.
"This storm has the potential to affect most of the country over the next few days," said MetService spokesman Steve Ready.
"Initially, the winds will strengthen from the north with a spell of heavy rain in the north and west of both islands. A severe weather warning has already been issued for the South Island West Coast."
By Wednesday much of the North Island should be buffeted by brisk westerlies and thundery showers, and by large ocean waves on its west coast.
"The ocean waves are likely to exceed six metres and to cause some large sweeping waves along the beach," Mr Ready said.
"They will be accompanied by strong onshore winds and squally showers making conditions unsafe for rock fishing or surfing. Boaties should also check their moorings."
Cold southerly winds, bringing rain and snow, will hit the south and east of the South Island on Wednesday, Mr Ready said.
Conditions are likely to ease on Thursday and Friday.
- NZPA
