Year after year it seems the seasons are shifting later and later. Whether that's just our long-term memory tricking us or something greater at play, we still see the seasons' end noted by the beginning/end of months. That being winter ending at the end of August and summer at the end of February.

Many cultures actually use the equinox or solstice to mark the end of one season and the beginning of the next. The equinox is when there is an equal amount day and night, while the the shortest and longest days of the years are called the winter and summer solstice respectively. These events usually fall between 20 to 23 days after the official ending of each season, with this year's spring equinox falling on the 22nd of September.

There is also a lag in the atmosphere from when we receive the least solar energy and experience our coldest weather, and similarly through summer regarding hot weather. This lag is even greater in the ocean, with warm water from summer lingering long into autumn and early winter, and vice versa.

So while winter officially finishes today, we've got the strongest cold outbreak of the year for the south-east of the country forecast for next week.

A very strong and pronounced node of the Long Wave Trough is expected to develop in the Bight and move slowly across the south-east corner of the country early next week, bringing with it cold weather, large swells and considerable snow dumps.

The node is expected to stall in the region for three or so days before pushing further east across New Zealand.

Currently the models have the node strongest when over Tasmania which will see a flurry of vigorous cold fronts projected up just to its west, initially into Southern Australian, and then Victoria.

Large stormy surf is expected to develop across the Southern Australian coastline from Sunday but more so into Monday and Tuesday with waves in the 8ft range due across the Victor Harbor region.

The Victorian coast will see the surf building through Monday initially out of the W/SW and likely reaching the 5-6ft range on the Surf Coast into the afternoon.

The angle of the frontal activity will swing more southerly into Tuesday and Wednesday as the LWT moves eastward, directing S/SW gales up into the region.

Larger surf to 6-8ft is expected at this stage on the Surf Coast with strong to gale-force winds from the western quadrant, favouring protected breaks.

Tasmania will receive the coldest air and start to see the swell building through Tuesday, with larger S/SW energy through Wednesday from the more favourably aligned southerly fetches.

The East Coast will only start to see swell once the frontal activity moves east of Tasmania and this looks to be during Tuesday evening, with moderate to large levels of S'ly swell due from later Wednesday onwards.

A quick look across the mountains reveals cold dry snow totalling 40cm+ by the end of the cold outbreak mid-week, reaching as low as 500m in New South Wales and Victoria, and 200m across Tasmania.

Keep an eye on the each local regions Forecaster Notes this Friday and Monday for updates on the expected timing and sizes of the incoming swells.