Millions of Australians are being warned to prepare for a ‘bomb cyclone’ which is set to wreak havoc across large swathes of the east coast. Severe weather warnings have been issued for NSW , eastern Victoria and southeast Queensland as the explosive ‘cyclone’ develops off the coast and heads inland. Damaging winds reaching up to 110km/h, along with large coastal swells and heavy rain are forecast to hit from Tuesday morning.

A bomb cyclone is a term used by meteorologists for bombogenesis, which refers to a storm that occurs when atmospheric pressure suddenly drops below a certain point. This creates a volatile, fast-flowing air mass which results in a rapidly developing storm. The pressure drop required for a bomb cyclone in the Tasman Sea, between Australia and New Zealand , is 18 hectopascals near Tasmania to 13 hectopascals near the Queensland-NSW border. This weather event will see the air pressure plunge by 22 and 24 hectopascals each day, which will lead to heavy rains and high winds.

Bureau of Meteorology forecaster Angus Hines explained that the powerful weather system would batter parts of NSW and Victoria from the start of the week, with up to 200mm of rain expected. Aussies should be prepared for Tuesday and Wednesday to be the two biggest days when it comes to rainfall and weather impacts. ‘On Monday, we’ll see the wind picking up and probably a few showers through the evening,’ he told Daily Mail Australia.

‘But Tuesday’s the day when it is really going to deteriorate, and it’s going to be very wet and very windy, so the rain will likely last through much of the day. ‘We will see the winds absolutely howling up that NSW coast. ‘We could certainly see those gusts upwards of 80, 90, even 100 kilometres per hour around parts of the Sydney Metro area on Tuesday – that’s definitely enough to cause a bit of damage, bring down some trees. ‘We could be talking about power outages as well.’ Aussies can expect the affects of the bomb cyclone to last through Thursday.

The most intense rainfalls are expected over the Central Coast, delivering up to 200mm of rain. Affected areas will stretch from the far south of the Mid North Coast, through the Eastern Hunter, Sydney, the Illawarra, and the South Coast, continuing all the way into Victoria’s Gippsland. ‘100 to 200mm of rain possible through these areas over 48 hours, and I expect some locations will pick up even more than that,’ Mr Hines said. A strong wind warning has been issued by the Bureau of Meteorology for the East Gippsland Coast in Victoria.

A severe weather warning has been issued in NSW for the Mid North Coast, Northern Tablelands and parts of Northern Rivers, Hunter, Metropolitan, Illawarra, South Coast and North West Slopes and Plains Forecast Districts. Damaging, locally destructive winds are expected along with heavy rainfall. Flood watches are in place have been issued for Mid North Coast, Hunter, Hawkesbury-Nepean, Sydney Illawarra Coast and Snowy catchments. A harzardous surf warning is also in place for the NSW Coast, along with a generalised warning for Lord Howe Island which is expected to be smashed with five metre waves. A marine wind warning is also in place for most of the Queensland coast.

Authorities have warned residents to expect a serious weather event. ‘We are prepared here at the State Emergency Service … but what we need is for you to be prepared,’ NSW SES deputy commissioner Debbie Platz said on Monday. ‘We have been monitoring this system since Thursday of last week and so our state emergency services, including our partner agency, are all very well prepared and planned for this event. ‘We have deployed high clearance vehicles, aerial assets and personnel into the areas which we think will be most impacted by this forecasted weather.’

Fallen trees and power lines are a particular hazard along with flash flooding. In a high wind weather system, NSW SES recommends securing loose outdoor furniture, bringing pets indoors, seeking shelter away from power lines and trees and low-lying areas, and only travelling if necessary. The forecasts have those impacted by last month’s devastating floods along the mid-North coast and Hunter region of NSW nervous.

Dairy farmer Michael Jeffery, whose sodden farm lies on the banks of the Macleay River, near Kempsey, said the rain was bringing people’s minds back to May’s catastrophic flood event. ‘It’s been raining all day already and that’s really got everybody on edge,’ he said. ‘It causes a lot of concern, because your livelihood is at risk, all the infrastructure on your farm that’s already been damaged by a flood and you worry about all your cattle and their wellbeing.’