Queensland and NSW residents are being warned to brace for a freak weather system which could dump up to 150mm of rain along the east coast, with fears of flash flooding in multiple regions.
Widespread rain and thunderstorms are expected to batter parts of ‘s east coast this week.
From Monday, the Bureau of Meteorology warns widespread and isolated thunderstorms could hit parts of central and eastern Queensland as an upper trough system interacts with deep moisture from the Coral Sea.
While the trough will likely track south down the east coast from Monday and move offshore on Wednesday, another trough is forecast to develop between Mackay and Hervey Bay on Monday or Tuesday.
Widespread 25-50mm falls have been forecast from Cairns to southeast Queensland.
But meteorologist Dean Narramore said the trough could stall over Monday or Tuesday, which would lead to heavier falls concentrated in central Queensland.
‘(They could) be up around 100-150mm, and possibly even higher than that,’ he said on Sunday.
‘Luckily… we’re not expecting a major flood scenario at this stage.’
A Flood Watch warning for South East Queensland coastal catchments are already in place, as minor flooding is possible in the areas from Monday.
‘There is a significant uncertainty in the timing and location of the rainfall, although the coast and adjacent ranges are most likely to see the heaviest falls,’ the warning read.
‘Localised river level rises and flash flooding are likely within the areas of heaviest rainfall, with isolated minor riverine flooding possible.’
Locals are being wanted flooding could disrupt transport and cause isolation to some communities.
The catchments likely to be affected include the Mary River, Noosa River, Sunshine Coast Rivers and Creeks, Pine and Caboolture Rivers, Upper Brisbane River, Lower Brisbane River, Logan and Albert Rivers and Gold Coast Rivers and Creeks.
Heavy rainfall is also expected to batter New South Wales’ Northern Rivers from Monday and into next week, with river level rises possible.
Minor flooding is possible in the Tweed and Rous Rivers, Wilsons River and the Richmond River
River levels are also slowly rising along the Lachlan River at Booligal Weir, with a prolonged minor flood peak likely in the next few days.
The river is currently at 2.53m and rising slowly and could peak at 2.60 metres in the next few days.
Marine wind warnings are also in place for coastal areas in Western , South , New South Wales and Tasmania on Monday.
While showers are likely to reach Melbourne by Wednesday, the mercury is forecast to reach 20C from Monday and into Thursday.
Temperatures in Sydney are likely to remain in the low 20s for much as the week as temperatures climb into the high 20s in Brisbane from Friday.
Perth and Adelaide will experience showers for much of the week while enjoying temperatures in the low 20s.
Temperatures in Hobart will reach a high of 20C on Tuesday.
Sydney
Monday: Partly cloudy. High chance of showers. Light winds. Max 20C.
Tuesday: Cloudy. High chance of showers, most likely in the morning. Light winds.Min 13C Max 20C.
Wednesday: Cloudy. Medium chance of showers, most likely in the morning and afternoon. Light winds. Min 13C Ma 20C.
Melbourne
Monday: Sunny. Winds northerly 20 to 30 km/h. Max 20C.
Tuesday: Mostly sunny. Winds northerly 20 to 30 km/h. Min 11C Max 20C.
Wednesday: Cloudy. Medium chance of showers, most likely in the afternoon and evening. Winds northerly 20 to 30 km/h. Min 13C Max 20C.
Brisbane
Monday: Cloudy. Very high chance of showers, becoming less likely in the evening. The chance of a thunderstorm. Winds southeasterly 15 to 20 km/h tending easterly 15 to 25 km/h in the middle of the day then increasing to 25 to 35 km/h in the late afternoon. Max 19C.
Tuesday: Cloudy. Very high chance of showers, most likely from the late morning. Winds easterly 25 to 40 km/h. Min 17C Max 22C.
Wednesday: Cloudy. Very high chance of rain. Winds easterly 20 to 30 km/h becoming light during the evening. Min 16C Max 22C.
Canberra
Monday: Partly cloudy. Slight chance of a shower, in the late afternoon and evening. Light winds. Ma 18C.
Tuesday: Partly cloudy. Slight chance of a shower. The chance of morning fog. Light winds. Min 4C Max 17C.
Wednesday: Cloudy. High chance of showers, most likely in the morning and afternoon. Light winds. Min 5C Max 16C.
Hobart
Monday: Mostly sunny. Winds north to northwesterly 15 to 20 km/h becoming light in the late afternoon then becoming north to northwesterly 15 to 20 km/h in the evening. Max 18C.
Tuesday: Mostly sunny morning. Slight chance of a shower, most likely at night. Winds northerly 20 to 30 km/h. Min 10C Max 20C.
Wednesday: Partly cloudy. Medium chance of showers. Winds north to northwesterly 15 to 20 km/h tending west to northwesterly during the morning then becoming light during the afternoon. Min 11C Max 18C.
Perth
Monday: Partly cloudy. High chance of showers, becoming less likely this evening. Winds westerly 20 to 30 km/h, increasing to 30 to 40 km/h near the coast, before decreasing to 15 to 20 km/h in the evening then becoming light in the late evening. Max 21C.
Tuesday: Partly cloudy. Very high chance of showers. Light winds becoming northwesterly 20 to 30 km/h in the morning. Min 12C Max 20C.
Wednesday: Cloudy. Very high chance of showers, most likely in the morning and afternoon. The chance of a thunderstorm in the southwest. Winds west to northwesterly 15 to 25 km/h tending west to southwesterly 25 to 40 km/h during the day. Min 13C Max 20C.
Adelaide
Monday: Mostly sunny. Winds northerly 20 to 30 km/h becoming light in the late afternoon then becoming northeasterly 15 to 20 km/h in the late evening. Max 23C.
Tuesday: Cloudy. Medium chance of showers, most likely in the afternoon and evening. Winds north to northeasterly 15 to 25 km/h tending north to northwesterly in the morning then becoming light in the late afternoon. Min 13C Max 21C.
Wednesday: Mostly sunny. Slight chance of a shower. Light winds becoming north to northwesterly 15 to 20 km/h during the morning then becoming light during the day. Min 12C Max 20C.
Darwin
Monday: Sunny. Winds southeasterly 15 to 25 km/h becoming light in the early afternoon. Max 33C.
Tuesday: Sunny. Light winds becoming east to southeasterly 15 to 20 km/h in the morning then becoming light in the late afternoon. Min 20C Max 33C.
Wednesday: Sunny. Light winds becoming north to northwesterly 15 to 20 km/h during the afternoon then becoming light during the evening. Min 20C Max 32C.