The Bureau of Meteorology has issued a severe weather warning for Sydney and much of the NSW coastline, from Moruya Heads in the South to Taree in the North, as a “vigorous” coastal low offshore brings damaging, locally destructive winds and possible heavy rainfall. In Sydney, heavy rain could bring six-hourly totals of 70 to 90 mm, while isolated downpours could see up to 120mm of rainfall. Wind gusts are already reaching up to 50km/h, and speeds between 60-70km/h are expected to set in on Tuesday afternoon, with peak gusts of up to 110km/h. Destructive wind gusts in excess of 125km/h could hit exposed coastal areas from Bondi to Wollongong from later today. Flash flooding is possible for the coastal fringe south of Seal Rocks on the Mid-North Coast and north of Ulladulla on the South Coast. NSW SES deputy commissioner Debbie Platz advised households to secure outdoor furniture, clear gutters, move vehicles away from large trees and download the Hazards Near Me app to stay up to date. The rapid intensification of the low into a fierce weather system, dubbed “bombogenesis” by meteorologists, is a rare event most often seen during winter. You can read more about the science of the phenomenon here. The forecast movement of the coastal low would see damaging winds and heavy rain persist into Wednesday.