A brief temperature spike to the low-30s, followed by a radical drop to the high-teens by the next day is expected in Melbourne to start off Autumn.

A low pressure trough currently bringing extensive storms over the west of the country will shift eastwards over the weekend and into this week. A hot airmass ahead of this trough will be drawn into Victoria on Sunday. Northerly winds bringing this inland heat into Melbourne look to raise temperatures to the low-30s.

A colder change will come late on Sunday as this trough increases cloud cover and a southerly wind change make their way over the city from the Southern Ocean. Following a quite dry day, with relative humidity around 30-40%, moist ocean air will quickly ramp up humidity into the 80% range.

Monday will be a much cooler, cloudy day in the high-teens, over a 10 degree temperature drop from the previous day. Along with this extreme change in conditions, brisk southerly winds will also bring an afternoon windchill making it feel a couple degrees colder than actual.

This cold airmass will gradually lose intensity as high pressure begins to build over the region, breaking up cloud cover and increasing solar heating by midweek.