Two waves of thunderstorms are expected to lash Sydney on Monday evening.
Wild and wet weather is expected to pass through Sydney on Monday afternoon and evening.
The city was expected to get the first of two waves of thunderstorms by early afternoon, with a second burst several hours later, Simon Louis, a Bureau of Meteorology forecaster, said.
The first batch of storms is likely to be fast moving, reducing the risk of local flash flooding, but the second wave will be slower, Mr Louis said, adding that there may also be some hail around.
Read Environment Editor Peter Hannam's earlier story on this evening's wild weather.
Our live blog will have all the updates as the storm descends.
The wild weather is likely to continue for the next day or so.
The Bureau of Meteorology has issued a severe weather warning for Tuesday afternoon, advising people to be wary of damaging winds, heavy rainfall and damaging surf in Sydney, north to the Hunter and south to the Illawarra.
Winds of around 70 km/h with peak gusts of 110 km/h are forecast for Tuesday afternoon.
On Monday the Bureau has also issued a severe thunderstorm warning for the state. Cities which may be affected include Scone, Mudgee, Bathurst, Katoomba, Gunnedah, Moree and Narrabri.
The Blue Mountains have so far felt the brunt of Monday's storm.
Residents in Katoomba reported their power was cut around 5pm, although it was back up around half an hour later.
And just like clockwork, we've lost power in the upper Blue Mountains. #storm #thirdworld
— Andrew (@andrewfaith) October 13, 2014
Massive thunderstorm just blew through Katoomba and took out the power. Guess we'll be filming the next scene by candlelight.
— Tony Stark (@darksilvercat) October 13, 2014
While power looks to have been restored, there are some lasting effects on roads in the area.
KATOOMBA: a number of traffic lights are flashing yellow on the #GreatWesternHwy in Katoomba - exercise caution and reduce speed. — Live Traffic Sydney (@LiveTrafficSyd) October 13, 2014
The first of two thunderstorms that were expected to pass through Sydney on Monday afternoon brought just a few rumbles over the south-west of the city.
"[The second] line's looking a little stronger," Bureau of Meteorology duty forecaster Simon Louis said. "We're expecting small hail, probably get briefly heavy rain but not long enough to cause any trouble."
He said the second wave of thunderstorms is expected to move through fairly quickly over the next half hour.
"As far as wind gusts, it could get up to around 70 to 80 km/h."
Mr Louis also said there was a southerly change moving up the coast behind the storm, bringing with it some cooler weather.
Crazy storm cell moving into Sydney from the Blue Mountains! #storm #rain #stormcell… http://t.co/cD4m4d7XTr — Justin McNamara (@CleanMind) October 13, 2014
A few great pics of the weather popping up on Twitter and Instagram. You can send your storm pictures to us at scoop@smh.com.au or tweet directly @smh.
#sydneystorm #armageddon #weather #australia pic.twitter.com/eajiNckhyH — Writer in Residence (@MikeCullen73) October 13, 2014
Storm rolling in over #Sydney pic.twitter.com/m7Y5B5Krrc — Murray Hurps (@Murray) October 13, 2014
Impressive cloud formation at the storm front... #sydney #storm pic.twitter.com/M5VVF0pv7P — Trevor Long (@trevorlong) October 13, 2014
SMH photographer and avid storm chaser Nick Moir is also out taking some great shots of the storm as it approaches Sydney.
Major storm enters #Sydney #weather pic.twitter.com/LUagktQ4N6 — Nick Moir (@nampix) October 13, 2014
Major squall line storm moves into #Sydney #weather pic.twitter.com/aMbtLhK8id — Nick Moir (@nampix) October 13, 2014
Transport in and around Sydney has been affected by the incoming storm.
A power surge on the Blue Mountains line has affected signalling between Emu Plains and Lawson, so passengers are advised to allow extra travel time.
A spokeswoman for Sydney Airport said there is currently a five nautical mile alert over the airport.
The alert means people aren't allowed out on the ramps and so ground staff are not able to load or unload bags, an airport spokeswoman said.
But planes can still take off and land so people should check with their airline on expected flight times, the spokeswoman said.
Heading home to Wellington but a bloody big storm's passing over Sydney Airport so we're stuck grounded for now :( pic.twitter.com/KZwUhKksvJ — Bob Buckham (@bobsyauncle) October 13, 2014
Our Twitter followers have pitched in tonight, sending in some great shots of the storm as it hits the city.
@smh pic.twitter.com/6tuWwKLLZZ — Murray Hurps (@Murray) October 13, 2014
@smh Xiao Bai here doesn't bat an eyelid at years of week long fire works in Beijing. But a thunderstorm worries him. pic.twitter.com/PEqHQAhVS7 — Richard Ford (@richardford) October 13, 2014
Minutes after this photo and we are getting smashed up at Somersby! @CCexpressadvoc @smh @SeaFM @Channel9 @9NewsSyd pic.twitter.com/6y2WRBYpoo — Jacqui Horne (@JacqHorne23) October 13, 2014
The latest on the storm is that it has now cleared the western suburbs and is moving quite fast toward the coast, Bureau of Meteorology duty forecaster Mick Logan said.
The coastal regions may be clear shortly.
A southerly change could bring more instability later on, but it looks like the storms will soon be done for the day.
The east coast low, though, should bring some more wild weather on Tuesday.
SMH reader Alex Cairncross has just sent us in this timelapse of the stormclouds over the CBD.
A warning for drivers across the metropolitan area, with several traffic lights reportedly out due to the severe weather.
SYDNEY: Exercise caution on Sydney roads, as a number of traffic lights are flashing yellow or blacked out due to the adverse weather. — Live Traffic Sydney (@LiveTrafficSyd) October 13, 2014
Fire and Rescue NSW is also reponding to reports of flooding and power lines down.
STORM | #FRNSW responding to multiple reports of weather-related incidents, including flooding & wires down. Take care out there. — Fire & Rescue NSW (@FRNSW) October 13, 2014
The NSW State Emergency Service received 117 calls for help across the city this evening, with the worst affected suburbs in the west and south west.
Spokesman Phil Campbell said there were reports of hail up to the size of 10 cent pieces in the Canterbury area, as well as some flash flooding and one tree across the road in Canterbury
While Monday's storms were brief, Mr Campbell said the SES was expecting to see more heavy rain on Tuesday and possibly a worsening of conditions.
He recommended people try to put away any loose items around the yard, to clean gutters and drainpipes if possible and park the car undercover.
If you need help from the SES the number is 132 500, or if the emergency is life-threatening call Triple-0.
A spokesman for Ausgrid said the storm had cut power to around 8000 homes in Sydney, mostly in the city's north around Turramurra, Pennant Hills and Eastwood.
At 8.30pm there were still around 6000 homes without power and crews were working to repair the damage.
The storm has mostly cleared out to sea.
With tonight's storm now out to sea, that's a wrap for our live-blog.
Forecasters predict another wet and windy day on Tuesday so check back in for more weather stories and photos tomorrow.
You can read our summary and see pictures of tonight's storm here.
