Topic: Sydney Coastal Thunderstorms : 21-22 May 2010

[Harley Pearman]

Sydney Coastal thunderstorms 21 May 2010

On 21 May 2010 some coastal thunderstorms developed around Sydney. As I was on flexi leave for the day, I was able to observe these and take some photos. Given that it is well into May and late Autumn, the cloud formations observed are reasonable for this time of the year.

The photos were taken on the roof of a car park in the centre of Blacktown 21/5/2010 from late morning till early afternoon. I observed up to 4 cloud to ground lightning strikes for the thunderstorm that was over Sydney City. The storm over Sydney dropped some 7.4 mm of rain at Observatory Hill.

The photos are taken looking south and east.

Harley Pearman

[Richary]

I was at Alexandria today on a course and we had one loud crack of thunder about lunchtime. But very little rain. Driving home just after 4 around Ultimo/Anzac Bridge it had obviously rained quite a bit recently, but nothing at home at Rydalmere. This has been very coastal the whole event with it doing nothing for the catchments.

Have spotted a bit of very distant lightning off the coast tonight coinciding with what is visible on radar/stormtracker.

Looks like continuous showers over the next week, with the chance of it getting a bit more inland and helping the catchments (hope it holds off tomorrow morning while I have to work near the Bridge). Just for the record the rain earlier this week totalled 28mm here at Rydalmere.

[Harley Pearman]

Sydney coastal storms (Afternoon of 21 May 2010)

Late Friday new coastal thunderstorms developed across Sydney's east or just off the coast. The photos are provided below. These were taken from 4 pm (Close to sunset) at Blacktown looking east. The sun has lit the western side of the cloud tower reasonably well.

Richary, this may be the storm that you were describing. At night, I was able to observe further lightning off the coast.

This activity was totally coastal and none of it penetrated into the western suburbs of Sydney. Rainfalls (From BOM for the 21 hours to 6 am 22/5/2010) include 35 mm at Cronulla, 26 mm at Narrabeen, 18 mm at Bondi and 17 mm in Sydney City.

I did note that further coastal thunderstorms occurred north of Sydney throughout the day as well as those across coastal Sydney.

Harley Pearman

[nzstorm]

Nice pics.  We get lots of those cold air cbs around Auckland over winter. 500mb temps -25C or colder over the warm sea tend to generate the instability and while coastal zones can catch the activity it dies a death as it moves over the cold land where the CAPE is zero. 

[Richary]

The pattern also continued Saturday morning and into the afternoon, even though no lightning was obvious from vantage points in Sydney itself. Stormtracker was showing some activity about 50km off the coast.

It is noteworthy in that near the city and eastern suburbs where I was working (Edgecliff) there were some very heavy showers coming across, and causing local flooding in some side streets, though this may have been more due to backed up drains than anything. At home near Parramatta rainfall was zero. Radar showed this activity continuing anywhere from the airport north through to Newcastle as a regular pattern all day, but hardly getting inland at all.

Today I was working in the city and while no rain, the cloud structures were still visible well offshore indicating this pattern has continued (I was on a couple of rooftops with good views to the east).