It’s a wild and woolly afternoon in Tasmania as a cold front approaches from the west, with winds gusting up to 148 km/h at 4:49pm on kunanyi/Mt Wellington above Hobart.

That’s the equivalent of a gust you’d expect in a category 2 cyclone, where the range is between 125 km/h and 164 km/h.

In Hobart itself, the peak afternoon gusts were only about half as strong, with a gust of 67 km/h in the city just after 2pm, and 70 km/h at the airport just before 5pm. Flights were still landing and taking off late on Thursday afternoon.

Elsewhere in Tasmania, wind gusts exceeded 100 km/h at numerous exposed mountain or coastal locations, including the notoriously windswept Maatsuyker Island off the state’s southwest tip, where a gust registered 124 km/h just before 5pm.

Why such wild winds in Tasmania this Thursday?

An intense low pressure system is situated over waters well south of Tasmania, pushing a polar airmass northwards. The tell-tale sign of the cold air is evident in the speckled cloud pattern in the loop below.

Meanwhile, much warmer air from the mainland is being dragged towards Tasmania in strong west to northwesterly winds, as air flows naturally from areas of high pressure to low pressure.

The steep pressure gradient between the areas of high and low pressure creates what the BoM calls a "squeezing effect", where the rapid, forced lifting of warm air by dense, incoming cold air has a similar effect to water in a garden hose which has been squeezed.

When will the winds die down?

The cold air is due later this evening, with fresh snowfalls for Tasmania down to about 1000 metres. While snow showers will persist for a day or so on the highest peaks, snowfalls won’t be as heavy as last weekend’s unusually heavy autumn event. Nor will snow fall to such low levels.

Winds are generally a little less gusty after the front has passed, although they will remain reasonably strong in exposed areas through Friday and into the weekend. However, it’s unlikely that the extreme winds of Thursday afternoon will be matched.

Hobart is expecting a maximum of just 14°C on Friday after it reached 20°C on Thursday in the mild air ahead of the cold front. Only a light shower or two is likely on Friday.