Wet weekend ahead for Canberra region, flooding possible on NSW South Coast

The Emergency Services Agency has warned Canberrans to prepare for heavy rainfall ahead.

"The community is encouraged to prepare now to minimise damage by ensuring all gutters are clear," an ESA spokesperson said.

"For those with existing damage from recent storm events, please be sure to tarp any areas where water may leak through."

Bureau of Meteorology duty forecaster Helen Kirkup said a large cloud mass sitting north of Canberra would likely bring 20 to 30mm to the territory on Friday.

"In the north west of NSW we've seen around 20mm already, in places that rarely see rainfall," she said.

"We could see higher rainfall and particularly up on the Brindabellas we could see a lot more, it gets enhanced as it comes up the ranges."

A dusting of snow could also be expected for the Brindabellas as the snow level drops to 1000m.

"The air mass isn't as cold as what gave Canberra a few snowflakes earlier in the week, it's a warm, windy air mass so it's only those higher places that we'll see snow falling," Ms Kirkup said.

A severe weather warning is currently in place for much of the South Coast and Snowy Mountains.

The Bureau forecast heavy rainfall could lead to flash flooding and riverine flooding.

Due to the slow movement of the low in the region, heavy rainfall is likely to continue throughout Sunday and possibly into early Monday.

Damaging winds west of the Alps are expected to reach more than 90km/h and average between 60 and 70km/h throughout Friday.

Similarly strong winds could hit the coastal fringe of the coast from Saturday.

Thunderstorms along the coast on Saturday could also lead to flash flooding.

Over the weekend a further 10 to 20mm is expected to fall in the Canberra region per day, before it will start to clear on Monday.

Ms Kirkup said a trough forming off the east coast would target rainfall to the NSW South Coast, where a flood watch was in place.

"Moruya and Bega are looking like the areas of most concern," Ms Kirkup said.

Parts of the south coast experienced widespread flooding and damage due to heavy rainfall two weeks ago, with some residents evacuated.