Yet another large storm is looking set to batter much of New Zealand in the coming days as a huge area of low pressure develops south of the South Island. The Radio Network’s head weather analyst Philip Duncan says both islands will experience severe weather later in the week but first up a relatively small low in the Tasman Sea will make for a wet day today. “This low pressure will move over the South Island during today – the mixture of warm and cold air may see some thunderstorms across the country especially in Taranaki and localised surface flooding is possible so drivers should be cautious if caught in a downpour”.

But Mr Duncan says once the low drifts south of New Zealand it will combine with another area of low pressure – creating a huge low the size of Australia. “We saw a low similar to this one in August last year, which brought winds of 135km/h to the far South. This one will be much closer to New Zealand and is likely to bring gale force winds, heavy rain and then snow to a number of places in both islands”.

First up will be heavy rain and strong nor westers developing in western regions of both islands by late Wednesday and throughout Thursday. By Friday the low is expected to become smaller in size but deeper in pressure. “Like a figure skater pulling their arms in and spinning faster so too will this low pressure system – the isobars will become closer together which indicates much stronger winds. Very strong south easterlies will develop over the South Island which could bring yet more snow to sea level across the weekend”.

Mr Duncan says huge swells along the South Island’s east coast will also develop during this weekend and could create “serious erosion” in some eastern beaches.

“This storm is one to watch, but one significant thing working in our favour is that it’s moving in an opposite direction to the major storm a few weeks ago. That means wind and rain will move in to different regions, many of which – like Taranaki – aren’t saturated like other areas such as Northland”.

The Weather Watch Centre will update regularly later in the week as the storm gets closer – allowing us to fine tune which regions will be most affected.