Almost 30 millimetres of rain fell within one hour in parts of Sydney on Thursday night as storms swept over the city, while areas to the north-west could experience minor flooding from Friday.
Amid the thunder and lightning, 29 millimetres fell in Canterbury and 24mm at Sydney Airport between 5pm and 6pm, while Richmond received 25mm in the two hours to 6pm.
Trains were delayed on Thursday night “due to severe thunderstorms and multiple lightning strikes damaging equipment at Sydenham”, Transport for NSW said in a travel alert.
The T2 Inner West and Leppington, T3 Bankstown, T4 Eastern Suburbs and Illawarra, and T8 Airport and South lines were affected. Repair crews were brought in to restore services.
On Friday, possible morning thunderstorms and further falls of up to 45mm are forecast in Sydney, Parramatta, Bondi and Liverpool, and up to 50mm in Penrith.
The Bureau of Meteorology has included the Hawkesbury and Lower Nepean Rivers in its flood watch, warning the catchments may be impacted by minor flooding.
“Rainfall is forecast to extend across the Hawkesbury-Nepean Valley, where flooding may develop from Friday into the weekend,” the bureau said.
“While forecast to stay way below March floods levels, it is still worth keeping a watch on updates.”