A burst of heavy rain and blustery winds will continue to batter eastern NSW over the next three days, with the state’s northeast coast set to see a particularly dangerous mix of rain, wind and surf on Friday and Saturday.

An upper-level trough interacting with a feed of tropical moisture caused rain to spread across a broad area of NSW over the last couple of days. The satellite images below show the cloud and rain associated with this system over the last 12 hours.

Video: Enhanced water vapour satellite and radar images showing cloud and rain over NSW on Wednesday night and Thursday morning.

In addition to this rain, a brisk southerly change has been making its way up the NSW coast on Thursday morning, whipping up huge waves and causing temperatures to plummet:

• According to observations from waverider buoy near Sydney’s Northern Beaches, maximum wave heights jumped by 5.5 metres in seven hours on Thursday morning.
• Sydney’s 8-day run above 24°C has also come to a bleak end. Most of Thursday morning has been feeling like 7 to 9°C in the city and the temperature is only forecast to reach 15°C in the afternoon.

Image: Sydney wave height observations, showing a rapid increase in wave heght on Thursday morning. Source: Manly Hydraulics.

Rain will continue to soak northern and eastern districts of NSW and parts of southern Qld on Thursday, before contracting towards northeast NSW and southeast Qld on Friday and Saturday as a low pressure trough deepens near the coast. Powerful winds and large waves will also persist along the NSW coast between now and Saturday.

There are also signs that a low pressure system could form off northeast NSW on Friday and linger near the coast on Saturday. If this low does form, it will cause heavy rain, potentially damaging winds and large waves in northeast NSW on Friday and Saturday. If the low moves far enough north, rain, wind and surf will also increase in parts of southeast Qld.

Image: Forecast accumulated rain between Thursday and Saturday, according to the ECMWF-HRES model.

Most forecast models expect the low to weaken on Sunday, which would allow wind and rain to ease in NSW and Qld.

Image: Forecast wind gusts early on Saturday morning, according to the ECMWF-HRES model.

It is worth noting that there is some uncertainty regarding the strength and position of this low pressure system, so forecasts may change over the next 48 to 72 hours. This system will be closely monitored by meteorologists and severe weather warnings will be issued if flooding or damaging winds are anticipated.

Be sure to check the latest forecasts and warnings over the next few days to stay up to date with the most accurate information.