Explosive Storms Developed across Sydney 3rd December 2014

Microburst Sydney near Horsley Park

Microburst Sydney near Horsley Park

Another very warm to hot and humid day across the Sydney basin provided the ingredients for more storms. The conditions were critical in requiring to overcome the cap holding the energy down across Sydney. The first storms developed southwest of Sydney and near Penrith. These obviously struggled initially. As they moved east though, they encountered an ideal environment with rich deep moisture and favourable directional low level shear. Suddenly, the storms exploded near Horsley Park. A second rain free base developed and this also let lose with a major microburst encountered. The storm complex continued to develop along a boundary that stretched north of Horsley Park. Flash flooding and extensive high rainfall of between 40 and 50mm of rain fell in the nearby Horsley Park region. 2cm hail was also reported by storm chasers in this region. Another intense cell also developed near Richmond but also dumped its load and produced further storm activity to its east. Eventually the storm complex weakened across Sydney. One of the features of this storm system was some intense lightning from well up into the anvils given the deep atmosphere.

Comments

comments

  • Con Marathos

    Great report there Jimmy, I managed to get to a local park in parramatta to see the storm over Horsley park .At around 4:40 it had quite a decent low level inflow band coming in from the east. Certainly showed quite good greenage . Strong outflow winds were followed by intense rain and lightning, a characteristic of many bolts was intense pulsing of the strike.

  • Con Marathos

    I’ve included two shots of a strike that pulsed at least 4 times. You can see it change direction as it switches back a quarter of the way down the channel.

  • Jeff Brislane

  • Jeff Brislane

  • Harley Pearman

    As discussed with Jimmy after the event, I was unable to see what occurred at Richmond or North West of Sydney however after I left work, I went up to the roof top of the Auburn City Council car park being a 9 storey building and had uninterrupted views of the event.

    This was a better outcome rather than deal with Sydney peak hour traffic.

    This was the first time I had seen such a storm event play out across Western Sydney from the roof top car park.

    I did not see the storm initiate but I did see an interesting shelf cloud approach from the west and south west. The storm seemed to move slow but had a general north east direction.

    I did see numerous cloud to ground lightning strikes as the storm system approached and I even saw distant green flashes as power lines or electricity substations suffered lightning strikes. I saw at least two occur.

  • Harley Pearman

    Another feature at Auburn was the large shelf cloud that was evident. The shelf cloud enlarged in size as it crossed west to east and further east, it seemed to partially detach from the storm. However, I did not risk taking photos and running across the roof top because some rather close lightning strikes had occurred.

    One such strike occurred on a crane near or adjacent to the Al Faisal College some 300 metres to the south of me and that produced a massive thunderclap.

    I also recorded three lightning strikes hitting a crane 390 metres from me on a development site at 6 to 14 Park Road which was interesting. I will describe that later.

    The rainfall built in intensity relatively slowly so it was not a downpour to begin with. However heavy rain did eventually fall as the main core passed over. I did not experience any hail. There was wind from downdrafts.

    I provide another picture of the base of the storm as it approached.

    At the time the photo was taken there was a large rain free base and it was relatively large.

  • Harley Pearman

    During this event and it must be a highlight, I captured three rapid succession lightning strikes on a crane situated at 6 to 14 Park Road. The images show the strike wrapping around the crane and two big strikes.

    The crane is on a development site only 390 metres to the west north west and two city blocks away.

    This morning, Council officers contacted the owner regarding the matter and the crane was checked for damage. It was confirmed that it did not sustain any significant damage. This highlights that one should never stand underneath cranes during storm events.

    This is the first time, I have managed to capture such an event.

  • Harley Pearman

    The final strike on the crane.

    What makes this sequence interesting is that the development site is next to Auburn Central being a residential flat building complex and a shopping centre below. With so many metal objects and telecommunication facilities in the area, it is amazing that the strike did not connect with the building so close to the crane.

  • Harley Pearman

    This thunderstorm produced some heavy rain but the heaviest falls were confined to Blacktown and nearby suburbs with falls of 50 mm to 56 mm. This includes 52 mm at Prospect, 54 mm at Merrylands West and 44 mm at Horsley Park.

    I have provided the rainfall plot for Sydney till 7 pm 3/12/2014. This is not the final figure for the 24 hours till 9 am 4/12/2014. It is the figure taking into account the storm event.

    There are areas that received little or no rainfall from this.

    I understand there was hail further west from this but at Auburn no hail occurred.

    Finally on the way home, I did pass through two intersections where traffic lights were blacked out on the Great Western Highway and I did note numerous fire trucks attending to emergencies created by this event.

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