According to Alex Zadnik from Weatherzone, the tropical low is drawing moisture-laden air from the Indian Ocean down to southern parts of the state, which will contribute to heavy rain and storm activity across the Grainbelt over the next 4-5 days.

“The approach of a cold front from the west will be the initial trigger for heavy rain and thunderstorms,” Zadnik said.

“Heavy rain and thunderstorms are expected to spread to the southwest of the state later in the week as the low tracks down the west coast” he said.

“Many parts of southern Western Australia average less than 20mm of rain for the month, but this upcoming system is expected to produce 7-day totals in excess of 100mm for some towns. There is the possibility that falls of this magnitude will occur within a two-day period,” Zadnik said.

“Given the amount and intensity of the forecast rain, flash flooding and riverine flooding are both strong possibilities, so residents should keep informed by monitoring weather warnings.”

The Weatherzone Meteorologist said that while heavy summer rain was certainly not a regular event in WA, it is not unheard of either.

“Tropical systems can be major contributors to one-off heavy rainfall events in southern WA if they coincide with the right steering flow of winds in the mid-latitudes. However, this system does have the potential to set new monthly and daily rainfall records through southern and central parts of the Southwest Land Division”