En bragende koldfront som blev dannet over de sydvestlige skråninger og i Blue Mountains ramte de vestlige forstader midt på eftermiddagen med ødelæggende vinde og hagl som forvandlede gader til snemarker.
Mere end 50cm hagl faldt over dele af det vestlige Sydney og børn lavede snemænd, rutchede i papkasser og kastede med snebolde.
Voksne mænd tog deres snowboards frem og startede ned ad en gade i Newtown.
Biler på M4, Princes Highway, Parramatta Rd og på Great Western Highway stoppede deres biler da hagl og voldsom blæst gjorde kørsel umulig.
Kommentar: Vi undskylder at resten af artiklen er på engelsk, men i vores bestræbelser på at få så meget information og spændende artikler ud som muligt, så må vi af og til ty til blot delvist oversatte artikler.
At Eastern Creek seven factories collapsed at Huntingwood Drive after 50cm of snow dumped on the areas.
Seven workers were lucky to make it out alive after the downpour.
"I couldn't believe it, it was like we were walking through snow," NSW Fire and Rescue's Supt Paul Johnstone said.
"I've never seen so much hail fall in one location. The factories just collapsed under the weight of the hail.
The SES has received more than 600 calls for assistance across the city after 4pm yesterday, and they were expecting many more as wild winds and rain lashed the eastern suburbs overnight.
Players at the Western Sydney Wanderers and Perth Glory A-League matched were forced from the field at Parramatta's Pirtek Stadium after hail stones turned the pitch into an ice rink.
Hail also forced Roosters and Dragons players from the field at Allianz Stadium.
"There has been some very heavy rainfalls within 10-minute windows, which has led to heavy localised flash flooding," Bureau of Meteorology forecaster Francois Geffroy said.
"A large portion of the metro was hit, with most the storms were out in the west and south. It mostly missed the north and eastern parts of the metropolitan region.
"The largest hail stones were 2cm or slightly bigger than that, but most hail was about 1cm."
Mr Geffroy said a sharp drop in temperatures aloft allowed much of the hail to fall to the ground.
The Inner West suburbs of Marrickville and Newtown were blanketed in hail stones, turning many of the streets into snowfields that reached knee height.
SES crews were also forced to do a flood rescue on Gordon St Marrickville after a person became trapped in their Mercedes.
The highest rainfall recorded was at Prospect Reservoir, which copped 53mm of rain between 3.45pm and 4.45pm.
There was also high rainfall at Blacktown (51mm), Greystanes (47mm) and Merrylands (36mm).
"A large portion of the metro was hit, with most the storms were out in the west and south and mostly missed the north and eastern parts of the metropolitan region," Mr Geffroy said.
More than 700 homes and businesses in parts of Berkeley Vale, Chittaway Bay and North Sydney were without power after the storm.
A NSW Police spokeswoman said officers received reports of water being up to car doors on Flood St in Leichhardt.
The roof of the Erskineville Hotel in the inner west also collapsed.
"At about 5pm we had some bad weather and then pub had to shut down," licensee Holly Hancock said.
"It was absolutely the busiest day of the year, so the pub was packed. It started to hail and the hailing put weight on the roof.
"One of the small rooms of the pub had a leak and a part of the roof collapsed. It was a collapse of about 1sq m.
"The water flooded into the pokies room, and then into the rest of the pub. There was about a foot of water so we had to ask everyone nicely to leave."
"Luckily it was a collapse in one of the smaller rooms, not the main bar. We have put tarps up and hope to have the pub open again tomorrow."
Public transport was thrown into chaos after trains had to be stopped at about 5pm between Chatswood and Wynyard.
"Some traffic lights are out but it is sporadic around different areas," a Transport NSW spokeswoman said.
"There was a lot of hail over roads and people pulled over but not causing any major traffic conditions.
"We have one airport line T2 impacted with trains not able to stop at Green Square because of flooding.
"There is a shuttle bus running between Mascot and Green Square.
"There was some delays with trains due to the power cuts, but no problems with buses."
Kommentar: Som det kan ses i vores månedlige videoresumeer om jordomvæltninger så sker disse begivenheder næsten dagligt, hvilket ikke var tilfældet tidligere. Er der noget på gærde?
Se også: SOTT Jordomvæltninger Video Resume - Marts 2015: Ekstremt Vejr, Planetens påstyr og Meteor Ildkugler