What is being dubbed as a ‘once in ten year Summer storm’ is forecast to hit South Australia tonight bringing heavy rain, flash flooding and damaging winds to large parts of the State. Above image ‘Rainfall forecast’ via OCF/BSCH
During Thursday afternoon, a frontal system is forecast to be located over South-East WA. During Thursday evening this front is forecast to move into Western SA and during the night its likely to move North-East to cover all of the State except for the Far North-East. Along this system, thunderstorms are likely to develop as hot temperatures combine with cooler more moist air from the Bight. Behind the system, heavy rain is likely to be generated as a constant moisture flow feeds in off the Bight and over land.
The kind of rainfall which is forecast to hit, especially areas such as the West Coast and Eyre Peninsula’s (both Lower and Eastern) is expected to be widespread falls of 25-50mm and isolated falls of up to 100mm. This kind of rainfall is typically only seen on a 1 in 10 year basis. Areas such as the North-West Pastoral, Mount Lofty Ranges, Mid North and Flinders are also expected to see heavy rainfall in the early hours of Friday with falls of 10-30mm widespread and isolated falls to 50mm not ruled out, falls in excess of 50mm are likely over the Mount Lofty Ranges.
Strong to damaging wind gusts of 60-90km/h are likely to accompany this system which may bring down some trees and cut power to homes. This system should also be responsible for bringing much cooler conditions to the State for the next few days.
A severe weather warning for heavy rain and damaging winds is currently active for this event, while a flood watch for localised road inundation, localised flash flooding and minor creek/river flooding is also active.