The low isn’t a storm, but it could bring 100km/h winds. How? It’s called a “squash zone” – the halfway mark between low pressure and nearby high pressure that produces a big area of straight line winds (unlike a storm where the gales circle the centre of the low).

These squash zone wind events tend to be quite widespread and the wind is a fairly forecastable block of wind – whereas “storms” often have pockets of severe winds and big lulls in the mix too. This ‘block’ of squash zone wind means it’s a bit more predictable and usually has fewer nasty surprises.

In saying that, we’re seeing reliable data that suggests gales with gusts to 100km/h are possible around eastern parts of coastal Auckland on Friday – especially in places like Mangawhai, Warkworth and Whangaparoa. This means there’s a moderate risk of power outages and branches or trees down on Friday north of the city.

In Auckland City itself the gusts may not be as strong but still 60 to 80km/h possible whilst marine areas may see gusts to 100km/h. Windiest parts of Auckland city will likely be the North Shore and eastern coastal suburbs.

The windy easterlies will blow across Friday with strong gusts in eastern Northland, eastern Waikato and Coromandel Peninsula too. But It eases overnight Friday and by Saturday much lighter winds means there’s a chance of afternoon thunderstorms and downpours.

• WeatherWatch.co.nz