A major late-spring storm will rapidly intensify later on Tuesday into Wednesday over portions of central and eastern New South Wales. This storm will threaten the Sydney metro area with damaging winds and flooding rains.
An upper low is moving through southeast Southern Australia now and is set to move across NSW through the next few days. It will spark rapid development of a strong surface low along the NSW coast. Moist onshore flow will dump torrential rains late Tuesday into Wednesday around the central coast of NSW, including Sydney. At this time it appears the heaviest rains up to 200 mm will fall just west and south of Sydney metro. However, flooding will be still be a major concern with totals up to around 80-140 mm in Sydney itself.
Strong south to southeast winds will also be a major hazard. Peak gusts of 80-100 kph will occur along the central and northern coasts of NSW and over the adjacent mountains. The combination of high winds and heavy rains loosening soil will lead to numerous trees down and power outages.