South Australia will get first taste of a cold, showery, windy burst which will plough through southeastern states in the next few days.
The south of the state will bear the brunt of a strong cold front as it rears up from the Southern Ocean.
Both Wednesday and Thursday are looking similarly cold and windy.
Adelaide is only likely to reach about 15 degrees on both days, which is seven degrees below the October average maximum. If it fails to reach 15.5 degrees it will be Adelaide's coldest pair of October days in nine years.
Wednesday will be the wettest day for most of the region, including Adelaide. When showers move through late morning it will cool to less than 10 degrees in the city and wind will make it feel colder more like seven degrees.
This will come as a shock to some, given winter is long gone and only last week Adelaide reached about 30 degrees.
Some showers will be briefly heavy and have potential to produce small hail.
There's even an outside chance of brief sleet or snow falling on Mt Lofty and on the Flinders Ranges, most likely during Wednesday night.
Overall, five-to-10mm of rain is likely in the Adelaide area with potential for more than 20mm, particularly in the Hills. The state's South East is also on target for five-to-20mm, but other districts look like picking up less.
During Thursday the pool of cold air will slowly head northeast, causing showers to become light in the Adelaide area and mostly clear elsewhere. However, brisk southerlies will persist, maintaining wind chill.
Regarding winds, gusts of up to 80km/h are possible in most areas, most likely about the coasts and hills. Kangaroo Island, southern Yorke Peninsula and Fleurieu Peninsula have the best chance for 90km/h winds, strong enough to bring down trees and power lines.
A warning to Sheep Graziers has been issued due to the threat of showers and cold winds.
Skies will clear and wind will ease on the weekend as a high pressure system takes over. By Sunday afternoon this cold may be a distant memory as the temperature in the city reaches 27 degrees.
© Weatherzone 2012
10:45 EDT El Nino is one extreme of the El Nino-Southern Oscillation (ENSO) phenomena, in which La Nina is its counterpart.