VIDEO: Westerly quarter winds driving our weather next several days

When the winds tilt SW they get cooler, when they tilt NW they get milder - welcome to spring and September’s weather pattern.

The next couple of days ahead sees milder airflows moving in before a cold front with some rain on Friday heads northwards.

What cold change?! NZ bounces back fast to warmer than average (+4 Maps)

Monday was cold for many regions with single digit highs. Tuesday morning saw some heavy frosts. Now Wednesday looks warmer than average while Thursday looks warmer still.

The ups and downs are due to changing wind directions and air flows caused by the chaos of spring.

VIDEO: Some nationwide warming up to do, but a split in who gets rain next

Low pressure around northern NZ is finally about to clear away with a spring-like westerly flow returning for the rest of the week.

This means a gradual warming up, especially in the eastern South Island which has a cold start to the working week but a fairly mild end.

Subtropical winds for very north, but Southern Ocean cold for Monday/Tuesday elsewhere (+3 Maps)

Updated 1:15pm: A colder change that spread northwards at the weekend means both Monday and Tuesday will be colder than normal in the east of both islands.

As said last week this cold air moving northwards will combine with warm rain caused by a northern low pressure system - this means heavy snow for the central/eastern ranges of the North Island.

VIDEO: Classic spring week: Lows, cold fronts and plenty of long dry spells

We have a typical spring week this week which kicks off with a low and rain in the north, has a colder than normal southerly in the east and the week ends on a windy westerly note with a cold front.

Overall it means wetter weather in the north and driest in the east of the South Island.

Sunday: Stark contrast of daytime highs as bitter southerly meets warm NWer (+5 Maps)

DETAILED UPDATE --- New Zealand has a complicated set up today with a fairly bitter cold change moving up much of the eastern side of both islands - but it's being caused by a high, not a low. Instead, the low in the Tasman is the culprit for the warmer than average day coming up for the top of the country.

Sunday's national forecast - Quite a cold day for some, much warmer and wetter for others

A low in the Tasman Sea is bring a windy weekend to the south eastern side of Australia and now it's about to bring wet weather to parts of NZ, mostly the North Island.

Massive electrical storm over Tasman Sea stands out globally, weakens as moves into NZ

Updated 2:27am Sunday --- Thousands of lightning flashes lit up the Tasman Sea on Saturday night and on a global scale it stood out as one of the largest on earth.

Sunday: A nation of two halves as cold moves into south, big low returns to north

Sunday is a great example of spring - it will be cold in the South Island and lower North Island while a low with mild nor'westers affects the upper North Island.

VIDEO: Another big low coming for the North Island, a cold Sunday for the South Island

We have one low departing and another one coming. This weekend sees a fairly dry Saturday with winds easing but Sunday sees the return of another big low coming in to the North Island while the South Island deals with quite a cold southerly change.