Thousands without power as severe weather lashes coast

Widespread heavy rain has triggered hundreds of emergency calls for help to the SES. (Tracey Nearmy/AAP PHOTOS)

Tens of thousands of people are preparing to spend the night without power as heavy rain, floods and unprecedented snow risk cutting access to parts of NSW.

Between 50 and 100mm of rain drenched parts of NSW's Mid North Coast and northern Hunter on Saturday, with more moderate totals across the coast.