Storm which hit Sydney started at Macquarie Pass.

I watched an amazing storm developing this afternoon. I drove out to the edge of Robertson, overlooking Macquarie Pass, to get a good look at it, before it really burst. Here is a link to the views from this same position, early in the evening, and at dawn. The views are amazingly different from tonight's storm.

Mt Macquarie, overlooking the Macquarie Pass, looks very imposing with a tiny patch of sunlight showing up the forest just underneath the cliff face. The white cloud was being whipped up and over the escarpment face. There were strong lightning bursts, every 3 or 4 minutes.
On the way back into Robbo, I listened to reports of water over the Princes Highway at Albion Park, then heavy downpours at Bellambi (northern Wollongong), and then it moved north, towards Sydney, 100 kilometres away. It took a little over an hour to get there.

This image shows a wall of water being dumped out of this thunderhead, over Albion Park and Dapto, just south of Wollongong. This was the peak intensity of the storm, from what I could see.
According to the Weather Bureau's website, tonight, Huntley Colliery (the other side of that bluff, at Mt Macquarie) reported 35 mm tonight, and Bellambi scored 46 mm of rain. Both from this single storm. Tonight the news reports are carrying stories of 100 Km per hour winds at Holdsworthy (southern edge of Sydney) and then it went to Blacktown, where people are still waiting to have their roofs repaired after the last big storm, in early December.

This is a panoramic image. Click to enlarge it, to see the "full picture" of this storm - it spans from Albion Park (under the clouds, far right) back to Mt Murray at the very far left of the picture. Wollongong is under the storm, in the middle of this image.
And this is what the local birds thought of it all. Yellow-tailed Black Cockatoos (Calyptorhynchus funereus) flew up out of the forests below the escarpment, heading north and west, away from the storm. Like the "Harpies" from a Greek tragedy, these birds were giving their full, drawn-out wailing cry. Very atmospheric.No sooner has these 3 birds flown past than a full flock (of 27 birds) flew up out from the valley below, also putting a lot of distance between themselves and the storm.

If you have ever seen these birds, you can possibly image how loud and ominous their combined 27 calls were. You can listen to the call by clicking here! Thanks to the "Birds in Backyards" website - from the Australian Museum (Sydney). The main site to the BiBY Bird Finder is permanently linked from the side bar of my blog.A very impressive ending to a very impressive storm.

POST-SCRIPT: The Illawarra Mercury has reported that the storm which I have witnessed here was caused by 3 separate storm cells merging.

• A merger of three storm cells south-west of Wollongong led to the extreme weather conditions across the Illawarra on Thursday afternoon.
• Bureau of Meteorology forecaster Chris Webb said that at 3pm on Thursday separate storm cells were recorded north of Nowra, south-west of Robertson and over Kiama.
• About 4pm the three cells came together around the Dapto area, resulting in strong winds, heavy rain and hail as the storm made its way north.

So there it is. You now know why this particular storm was so powerful. You can read the full report here.