Parts of central Australia, particularly South Australia, are in for a good soaking later this week and throughout the weekend.
Some areas may see two to three times their monthly rainfall for July, with the potential for some locations to see their highest daily rainfall totals in history.
Locations like Woomera, whose median July rainfall is only 9.3mm, are forecast to see up to 30mm from this event. Likewise, Tarcoola averages 7.9mm for the month and is forecast to see up to 35 mm, with Andamooka's July average just 6.2mm, with up to 30mm forecast to fall on Saturday alone. However, this highly depends on rainfall hitting some of these more remote regions' automated weather stations.
Accumulated rainfall totals the next several days. ACCESS G, GFS, OCF, ICON. Images via WeatherWatch MetCentre.
The reason for all the rain?
A rather large cut-off low and associated cold pool of air will slowly drift through western parts of South Australia in the coming days and strengthen slightly. To its southeast, a large, dominant area of high pressure will reside near Tasmania and extend a ridge north across the eastern states. As this large fetch of moisture-laden east-southeasterly winds moves inland, it will shift to the northeast, funnelling air into the upper cut-off low across western South Australia. This will see an increase in clouds, showers, and rain periods.
An upper cut-off low is situated across western SA, drawing moisture-laden air to its east. Image via WeatherWatch MetCentre.
Rainy conditions will see maximum temperatures in the teens during the day, although overnight minimums will likely be warmer under cloudy skies.
OCF forecast maximum temperatures for Saturday and minimum temperatures for Sunday. Images via WeatherWatch MetCentre.
Either way, winter rainfall of this nature will be more than welcome, considering the recent lack of rainfall that has affected South Australia. During the past 3 months alone, rainfall deficiencies were recorded for large regions of southern and central South Australia that were very much below average to lowest on record.
Although this upcoming rainfall won't completely alleviate the ongoing drought that has been affecting large portions of the state in recent times, it will certainly help.
3-monthly rainfall deficiencies across South Australia. Image via Bureau of Meteorology.