The Illawarra is in for wet, cool and windy conditions today with up to 50 millimetres of rain and possibly a thunderstorm.
Grace Legge from the Weather Bureau said we can expect some extensive rainfall and a top of 19.
"We do have quite a hefty air mass moving through," she said.
"There's quite a lot of rainfall further to the east and it will be extending into the Wollongong area, Legge said.
"With that we could see some decent falls throughout the area, most likely we'll see widespread falls of 20 to 40 millimetres.
"If you do get hit by a thunderstorm then it will be even a little bit higher, potentially seeing rainfalls of 50 millimetres or so," she said.
Legge said things will improve for those heading to Wings over Illawarra at Shellharbour Airport this weekend but a decent southerly is forecast for tomorrow with a top of 17.
"There's still a chance of seeing a morning shower Saturday but overall, pretty much an easing trend from then on.
"There's still possible showers but most likely really in the morning period and just a couple of millimetres.
"Then on Sunday, just a medium chance of showers, once again most likely in the morning and clearing up in the afternoon," she said.
Despite the forecast, volunteers at HARS Aviation Museum have been busy preparing for the airshow which opens at 9am tomorrow.
They will have almost 50 aircraft on display over the two days.
Many of their aircraft will be on the tarmac outside the museum with others in two large hangars which will also provide attendees with refuge if they need it from sun or rain.
A southerly will ramp up today and blow for the next few days.
"It does continue to pick up tomorrow with southerly winds of 25 to 45 kilometres an hour pushing through," Legge said.
"It will ease back on Sunday though becoming light by the time you get to Sunday afternoon and evening," she said.
A hazardous surf warning is in place for the Illawarra Coast.
The Weather Bureau is forecasting conditions to worsen across the day and remain that way until Sunday.
The BOM is advising people should consider staying out of the water and avoid walking near surf-exposed areas.
Images: HARS, Travis Winks and windy.com