Another wet weekend as BOM issues severe weather warning from Perth up to Jurien Bay

Australia Broadcast Center

a day ago

Weekends in Perth have been gloomy of late and this one is no exception, with wet weather predicted for the metropolitan area up to Jurien Bay from Saturday afternoon.
Authorities are also keeping a close watch on the Avon Descent in case the deluge reaches further inland and causes river levels to rise during the weekend white water event.
The Bureau of Meteorology has issued a severe weather warning for heavy rainfall with flooding possible for the Lower West, including Perth, southern parts of the Central West and far western parts of the Central Wheatbelt.
Locations that could be most affected include Perth, Gingin, Jurien Bay, Lancelin, Badgingarra, Rottnest Island, Yanchep, Armadale, Ellenbrook, Fremantle, Joondalup and Kalamunda.
The bureau said 20 to 35 millimetres of rainfall over a six-hour period was likely with possible isolated totals of 60mm as a cloud band is followed by a weak cold front.
The coastal fishing town of Lancelin, around 125 kilometres north-west of Perth, recorded 44mm of rainfall in the three hours to 9:45am on Saturday morning.
Bureau forecaster, Angeline Prasad, said the main impact from the weather system was the potential for flash flooding, especially if the system moves further south.
"We have seen quite a few fronts move through the South-West, including the Lower West recently, so in some locations the ground is fully soaked, so any more rainfall is going to cause water in the landscape," she said.
"So the main risk from these heavy falls that we may experience from late this morning into the afternoon period will be flash flooding."
Ms Prasad said there was also the chance of thunderstorms in the warning area, which could add to the deluge.
"Thunderstorms are likely to be quite gusty, there's a smaller risk of damaging winds, but the main risk that we're worried about is the heavier falls."
Ms Prasad said the approaching cold front, behind the cloud band, was likely to move through on Saturday evening and overnight before continuing into the state's south-west on Sunday.
She said the cold front would bring widespread rain to a large swathe of southern and central WA.
It would possibly dump between 10 to 20mm of rain on the Central West, South West and South West Goldfields as it moved east, but Sunday's rainfall was mainly expected to stay in the 5 to10mm range she said.
While recent rainfall did not seriously impact the first day of the Avon Descent, Ms Prasad said heavy falls could potentially reach far enough inland and increase the river levels for the second day of the white water event.
"The Avon Descent is through the Swan River so the severe weather warning does extend over the catchment … it is possible that we will see rises in the river over the next 24 hours with this type of rainfall," she said.
"At this stage we're not looking at issuing a flood watch but it's something that we'll keep in mind, especially if those heavier falls extend further inland.
"At this stage, I'm expecting the heavier falls to stay along the coast, but it's something that we're watching very closely."
Those in Perth or coastal parts of WA's south have endured a wet, and sometimes wild, winter.
However, Ms Prasad said those weather systems were not travelling far enough inland to get rain to much of the state's agricultural areas.
"This winter has been wetter than normal across some parts of the western South Coast but there are still vast areas inland of the South West land division that haven't seen the rainfall they should have," she said.
"Inland parts have had rainfall but in dribs and drabs.
"So what's been happening is we have seen quite a few strong cold fronts and quite frequent frontal activity this winter but as the fronts have moved inland, they have weakened off fairly rapidly," she said.
"So we're still travelling below average for large agricultural areas over inland parts of the South West Land Division."