An East Coast Low (ECL) is brewing off the NSW coast on Monday, set to deepen on Tuesday and move away from the coast later on Wednesday.
This will be a major weather system.
These beasts develop rapidly, and bring torrential rain and flooding, damaging winds, and coastal effects like hazardous surf, erosion and coastal inundation.
MONDAY
On Monday we have the system setting itself up.
Rain is spreading across Queensland showing the moisture that is feeding into this system, while a cold pool of air crossing the southeast brings the energy. The warmer than average waters of the Tasman Sea is the stage that this moisture and instability will play out on.
By later tonight we see the ECL form, likely to be located off the northern NSW coast. Once the low forms the rain wraps around it and affects those areas to its south - down to about Newcastle, NSW.
TUESDAY
The low slowly moves southwards overnight and during the day on Tuesday, heading away from the coast in the afternoon and evening but deepening as it does.
This spreads the rain further southwards - as rain with and ECL is adjacent to and south of the low. Tuesday's rain spreads through the NSW Central Coast, Newcastle, Sydney, Wollongong and much of the NSW South Coast. Queensland and far northern NSW turn quiet as they are now north of the low.
WEDNESDAY
The low is likely to hover between about Newcastle and Sydney on Wednesday before moving further away in the afternoon and evening.
This pattern means the heaviest rain is for Sydney and southwards, all through the South Coast, around the corner into Gippsland and brushing the northeast corner of Tasmania.
THURSDAY
There may be one last push from this system on Thursday as a second ECL centre is just close enough to the coast to bring further rain from about Coffs Harbour in NSW through to Sale in Victoria.
SUMMARY
All up we're likely to see falls well over 100mm, potentially in the 200-300mm range between southern Sydney and Batemans Bay. Falls over 50mm are likely from Sale in Victoria up to Coffs Harbour in NSW. Falls in northeast Tasmania are less, unless the low travels further south.
Keep up to date with the latest warnings for:
- flooding
- damaging winds
- coastal gales
- hazardous surf
- erosion
