Update Thursday 4.40pm
A spokesman the Bureau of Meteorology has advised that 82mm has fallen at Murrays Flat, just north of Goulburn, over three hours.
"That is the stand-out across NSW at the moment," he said.
Over the same period, Mount Gray at North Goulburn received 33mm, the Goulburn Water Treatment Plant - 20mm, Goulburn Airport - 5.6mm and Big Hill - 25mm. By contrast, Taralga hadn't received a drop and only 1.8mm fell at Sooley Dam.
But heavy falls and hail were expected north of Marulan and towards Bowral where the storm was headed.
"Humidity combining with favourable conditions in the upper atmosphere have created the instability," the spokesman said.
Meantime, Goulburn SES reported that it was attending 35 to 40 call-outs this afternoon. While crews attended to leaking roofs, they were also called to a Healey Street home which was inundated with water. At another home, duty officer Steve Watson said a fridge was "floating' in one metre of water.
The council has also just advised that all roads closed earlier have been re-opened.
Update Thursday 3.55pm
South Eastern Operations Manager, Darren Basterfield said Essential Energy crews responded to an unplanned power outage affecting 856 customers in Goulburn this afternoon.
"Network protection equipment activated at 12.53pm to isolate supply to the area after detecting a fault on the high voltage electricity network due to the severe storm activity," Mr Basterfield said.
"Crews secured the safety of the site, repaired the network and began to progressively restore supply to the majority of customers by 2:56pm.
"Supply was restored to all customers by 3:15pm."
Update Thursday 3.25pm
Some 58 houses in the Goulburn area are reported to be without power after a storm this afternoon.
Areas affected include Kingsdale, Goulburn Airport and South Goulburn.
Shops along Auburn Street have also been affected by the rain, with the majority of the flooding coming through the stores.
Blooms the Chemist opposite Belmore Park had to stack towels on their back door to clean up the water that had flooded.
“Trade has come to a complete halt,” worker Hassan Ajami said.
"We have also had blackouts on and off.
“We were lucky to have UPS Systems Australia because that prevented our computers from stopping.
Mr Ajami hoped Goulburn Mulwaree Council would do something about their ineffective pipelines.
"They need to clean up the pipes and fix them," Mr Ajama said.'
The back half of Bi-Rite Electrical Goulburn was completely soaked with water that had flooded through the back door.
“We will have to use a lot of towels to dry up the water.
“This is worse than back in January.
Update Thursday 2.30pm
The Bureau of Meteorology has advised that Goulburn received about 36mm in 30 minutes during the intense burst of the recent storm.
"Our rain gauge at Murray's Flat received 36mm in one hour and 30mm of that was in a 30-minute period," the BOM spokesperson said.
It seems like the rain was very localised to the north of the city though, with the Airport gauge receiving only 5mm.
Meanwhile, the Goulburn SES said they were responding to about 29 jobs at the moment.
"We have had a house in Stalker St, Goulburn receive major flooding. About one metre of water went through it," the SES spokesperson said.
"There are also many reports of flooding in house roofs, but no major accidents or cars going into flood waters at this stage."
Update Thursday 2pm
The sacristy at Saint Saviour's Cathedral and the Mesac Thomas chapel on the northern side has experienced heavy water inundation.
Cathedral Dean, The Very Reverend Phillp Saunders said the rain poured in through the ceiling and flooded the chapel and then flowed down the steps into the church and drenched carpet.
"We think the hail blocked the down pipes," he said.
Water was also cascading down several walls.
Parishioner John McCulloch was busy mopping up water around the sacristy when the Goulburn Post visited.
It's the second downpour the Cathedral has coped with in a short timeframe. On January 9, more than 40mm fell in just three hours, flooding businesses and streets.
The Very Reverend Saunders said on that occasion the rain flooded the church's entry way.
The Cathedral has recently undertaken extensive work to address internal damp problems.
The SES has been contacted.
The council has advised that Rifle Range Road, the Blackshaw Road underpass, Middle Arm Road, Marys Mount Road, Yarrowlow Street and Stalker Street have been closed.
Residents of these roads and streets will be allowed home.
Council crews are also checking other rural roads and infrastructure.
Update will be provided on the council's Facebook page.
A massive storm has come through Goulburn today.
Hail and rainfall around 1pm has caused flooding and power outages across the district.
The SES reports there is major flooding in St Saviour's cathedral.
The Disability Trust is another building affected.
There are also reports of houses and businesses being affected with power outages.
More to come.