The Swiss Cheese Effect - How to read NZ's Seasonal/Monthly forecasts and get more from them

We all know the generic forecast that often gets it wrong. "A dry weekend" says the weather - then you get a downpour and your gutters overflow. Welcome to New Zealand and why forecasters age here faster than most nations on earth!

VIDEO: Southern Ocean storm to affect NZ until Sunday

We have the latest on the deep storm in the Southern Ocean. While it’s a long way from the North Island it will send a burst of rain there today but the days ahead don’t look too bad.

The South Island, on the other hand, has more heavy rain on the West Coast off and on until Sunday.

Southern Ocean storm: 9 Latest Maps + Forecast

Up to 250mm has fallen in some parts of the Southern Alps in just the past 24 hours and over the next few days another 250mm is coming. Today is likely to be the windiest day nationwide but the winds are warm, pushing much of the country above normal temperature-wise today and the whole country will again be above normal tonight.

VIDEO: Southern Ocean storm to alter NZ’s weather for a week

Special detailed update --- A storm is south of New Zealand but not everyone has bad weather this week, in fact some have more sun, dry and warmth while others have heavy rain and gales.

Sub-tropical winds keep temperatures above normal day and night (+Animation)

Thought last night was warm, or this morning? The sub-tropical flow that covers most of New Zealand is pushing temperatures well above normal nationwide and despite it easing across today in the South Island it may not be clearing from northern NZ all that fast.

Big doesn't always mean bad for everyone as Southern Ocean storm forms (+3 Maps)

UPDATED 7:51am Monday --- A huge area of low pressure is forming in the Southern Ocean creating a large storm which will span thousands of kilometres in diameter and brush New Zealand and south eastern Australia. It will affect our weather for about seven full days.

The storm itself won't directly cross NZ, but it's so large in size it can't help but swipe us.

Sunday's national forecast

The weather is going downhill today in the South Island but the increased wind flow will also boost daytime highs in the east of both islands, especially the North Island.

Australia's smokey haze to continue lingering across NZ (+InfoGraphics)

As dozens of Australian fires continue to burn, some out of control, the air pressure set up over the Tasman Sea means New Zealand's skies continue to be polluted.

VIDEO: Huge Southern Ocean storm to dominate NZ’s weather next week

A very large area of low pressure is forming in the Southern Ocean and next week it will churn south of NZ but push severe weather at times into New Zealand.

Heavy rain on the West Coast, strong to gale force nor’westers move up the South Island and lower North Island and some rain into northern NZ too (not a huge amount, but some).

VIDEO: A cooler Friday for some, stormier next week in the south

NZ remains warmer than normal but on Friday a cooler change moves up the eastern South Island dropping temperatures in coastal areas by over 12 degrees.

This weekend we see a few heavy downpours inland with possible thunder.