Topic: Storm Chase in Western Sydney - 11th December 2006

[Jimmy Deguara]

Hi,

I borrowed another car - yes another green Camry.

Basically pulse storms today though I must say I was impressed with the 700 to 500hPa lapse rates. I met Nick under the first cell near Kemps Creek and it looked half decent in terms of producing a base. Some large drops of rain (melted hail) and gradually increasing lightning activity! The cell merged and intensified near Fairfield where some impressive staccato bolts were recorded on film.

I then headed out to Picton turn off and towards Menangle and another cell intensified. Some impressive bolts but only few could be captured. Near Campbelltown, the rain was quite heavy and the lightning activity was also impressive - missed opportunities here as well.

Another barrage of lighting near Hoxton Park (where I noted my video footage was slightly out of focus). I must say for brief period, the lightning frequency matched January 2004 - per unit area perhaps?

However, it was not until I got to Schofields where amazingly lightning active cell was in place! No rain so easy to capture lightning. I had video and camera taking what I can before the activity receded. Some nice staccatos. Here are some of the pictures:









Regards,

Jimmy Deguara

[David C]

I headed out from work (North Ryde), meandering through the back-streets, and west towards  Silverwater. The storms around were high based and looked weak so i decided to head back towards the lookout at Ryde-Eastwood. Over the next hour the storm organised nicely and, as Jimmy suggested, the steep mid-level lapse rates resulted in some impressive updrafts. I liked the fresh NE infeed and it wasn't long before a substantial base developed. (following are all video stills)




At this stage lightning was infrequent, although I also noticed some similarities with January in 2004 - I was expecting an intense lightning show and was not dissapointed.










Another look at the very reasonable updraft base






and some more lightning:







Another perhaps even more active cell moved through the south-west suburbs at around 8:00pm or so - ran out of tape at that point 

[Jimmy Deguara]

Hi David,

Nice staccato lightning. At least finally a storm happened to intercept the Sydney region.

I have not looked through the video yet but I suspect some very impressive lightning stills to come out of the footage!

Regards,

Jimmy Deguara

[Matthew Piper]

The thunderstorm at 8pm delivered an intense barrage of CG's to Liverpool  One particular bolt sounded like it hit a block of units nearby it was so loud. My wife and I both nearly jumped out of our skins we were so startled  I witnessed the earlier storm from the M4 as I was coming back to Liverpool from visiting my parents in the Blue Mountains. There was a number of really visible CG's in this storm and the one in the evening due to the high storm bases.

[vrondes]

Hello Jimmy and David,
Impressive captures of lightning from yesterdays storms.  Glad to see that nothing stops Jimmy from recording a memorable day of lightning.  Your efforts were well rewarded. David, what impresses with video is that you can capture the full strike with all the branching, whereas with daylight lightning shot with a still camera  seems difficult to capture that 1st half a second of the strike where all the branching is evident. I need quicker reflexes or a lightning trigger. great lookout spot, is that the one in Denistone?. The three  storms that were visible from parramatta went through at 5pm, and 7pm and the final one to the northwest at 8pm were very photogenic. . The first two being high based were very dynamic, and the 8pm show had prolific staccato strikes, unfortunately due to babysitting commitments, homebased meant that photgraphing lightning will have to wait till another day.  looking forward to your video captures too Jimmy.Cheers, Con.

[Harley Pearman]

David and Jimmy

You have captured some very impressive lightning strikes from a distance.

Because I have had such a poor season, I decided after work to drive right up to the base of the storm, drove underneath it and parked the car. I was at Mona Park (Chisholm Road Auburn). I made sure that I was underneath the darkest part of the cloud.

Before I left work at 4.50 pm, I noted the temperature where I was:-

Homebush - 32C
Due Points - 15C
Humidity - Rising to around 56%

While I did not have my video camera with me I had my SLR camera and took a photo just before it became far too dangerous for me to get out of the car.

All those lightning strikes you were filming and recording were actually hitting objects very close to me. Not to understate this, I received no less than 7 explosive or major thunderclaps in a row.

One lightning flash about 100 - 150 metres away to my west made the car shake and set the car alarm off. It did something to the car alarm.

Oh, I then watched 2 women and 2 girls walk past my Council car all carrying steel umbrellas. I thought that this was so stupid especially since the storm was producing staccato lightning in the locality where I was. I trained my camera on them thinking that I would actually witness a lightning strike fatality but they were so lucky. Even another massive strike near me did not deter them and they wandered off.

Later that night (Between 8 and 8.30 pm), I took some video film of that south western thunderstorm and captured some lovely lightning flashes before the lightning ceased. So I am pleased to have seen at last, a storm and filmed some lightning.

It was interesting to see how that first storm developed. In particular, they started off as a line of cumulus towers over the Blue Mountains. After enlarging, I noted significant weakening then the cell that produced the lightning that you filmed developed at the rear of that first line. Yes it was high based.

The storm produced large raindrops where I was but no hail.

The thunderstorm cell weakened further east and I agree with Jimmy, it was a pulse storm, one of many that had life spans of say 30 minutes to 1 hour.

I also noted the top temperature range for the day for Sydney, eg

Manly 22C
Sydney Harbour 21.8C
Observatory Hill 28C
Homebush 36C
Parramatta 37.5C
Blacktown 39C
Liverpool 39C
Penrith 40.3C

The storms formed over western Sydney in an area that had received significant daytime heating but weakened by the time they reached the coast. I think the sea breeze effect may have had something to do with that. There was certainly a significant temperature gradient across Sydney and no doubt this influenced what happened. Yet humidity levels on the coast was 57% before 3 pm but just 14% at Penrith but yet these storms formed in a region of lower humidity but higher temperature. Given the fact that I was watching some of the dynamics of what was going on, I was able to note this wide contrast and variation. This is something that I have never noted before.


Harley Pearman

[David C]

Hi Con,

Denistone --that's the one. It's a very good lookout when fast-moving storms are tracking NE (and in the field of view). Yesterday, storms propagated slowly and, fortunately, the most active phase was in full view -- I was quite lucky in that respect. (What made it all the more enjoyable were all the storm-birds (cuckoos) going crazy ie Koel and Channel Billed types.) With this lookout there is the option of moving east to the Victoria Road overpass at Blaxland Road when storms track SE

 Yes, I think you would need inhuman reflexes to catch a daytime staccato - part of the fun with video is going back frame-by-frame and occasionally revealing a staccato flang that wasn't even seen with the naked eye. One thing, there is a certain structural quality characteristic to these highish-based and prolific electrical storms -- there was no doubt that once that concave, rippled base developed it was going to go ballistic with Cgs.

Cheers Harley - definitely dangerous yesterday as far as lightning is concerned!

[Jimmy Deguara]

Hi Harley,

You are correct about the steep temperature gradient across Sydney. I would say that yesterday's storm situation was unique in some respects. We were able to observe the importance of outflow boundaries initiating new cells. In fact had the outflow boundaries not been in place I very much doubt southwest Sydney would have had so many cells. In fact the contrast was quite pronounced with any location north of the Great Western Highway say at least west of Prospect would have received little if any rainfall. Yes some rain did come through overnight totalling in my case 1.2mm of rainfall.

Regards,

Jimmy Deguara

[Michael Bath]

Why do you say unique Jimmy - this type of event?  28th Nov was very similar in the Clarance Valley.

Lovely CG photos and captures
David - your video does excellent stills ! 

MB

[David C]

Why do you say unique Jimmy - this type of event?  28th Nov was very similar in the Clarance Valley.

Lovely CG photos and captures
David - your video does excellent stills ! 

MB

Taa Michael! Those are frame grabs from the FX1 in standard definition mode.

Perhaps Jimmy means unique for Sydney in 2006    well it is basically the only storm we have had that is worth documenting

[microburst22]

I would have loved to have been out there chasing those storms.
Loved the lightning shots thanks Jimmy.
However watching the storm come in over the city is fine for me.
Im still waiting for more frequency in the storms.

From Amanda

[australiasevereweather]

Michael and David,

What I meant by unique is the presence of an outflow boundary playing an important role in a weak sheared environment and yes within the region that is not consisting of open plains. Why didn't the storms develop and remain on the ranges as pulse storms? Sure there was a touch of wind but in normal circumstances, storms would send across anvils and that's it. I believe that without the presence of outflow, the southwestern suburbs would not have received such widespread storms.

Regards,

Jimmy Deguara

[Dave Nelson]

Hi Gang,

    We (inc. wife and daughter) went out to the rooftop carpark at Centro Seven Hills for the first (5-6pm). Only got a brief burst of rain there as we were on the nthrn edge of that cell.  Yes Dave C.,  I saw that rippled base too and thought  this could be good!!.   The rooftop gave a good 360 deg clear view. captured some good CG's from the first cell as it passd to the south of us and then over the top of Harley. A smaller cell passed almost directly overhead and  produced a few good CG's.  There was a large cell passing across the NW of the city and could be seen on the radar to be moving from ~ Lithgow towards Gosford.

   Heading home to start editing the avi movie clips, it was ~ 7pm when a loud rumble of thunder got me away from the computer  to see what was happening outside.   There was a cell moving in from the west and heading virtually right for me in West Ryde.  Proceeded to capture a bunch more lightning strikes. VERY active. a and 5 minute burst of heavy rain (no hail).

 The 3rd session for the evening took us (daughter and I) up to the Dural area where yet another active cell passed across the far northern areas of the city.  Although I didnt get any pix from this activity, it was a treat to watch the wonderful
zaps across the sky as CC's and CG's

cheers
Dave N

[Jimmy Deguara]

Hi Dave,

That storm near Dural was an active cell! Did you find it more active than the others in your opinion? And for a prolonged period?

Regards,

Jimmy Deguara

[Dave Nelson]

Hi Jimmy,

   Yes for a period of time it was quite active.  At least comparable with the storm we watched from Seven Hills ~ the 1700-1800hrs EDT. But it didnt last as long main activity period maybe 30-45mins.  In fact, in the ~ 30mins it took to get from the Paramatta River jetty (at the end of Wharf Rd, West Ryde) to Dural, the activity had dropped to maybe only 25% of what was being observed during the travel to Dural. We (daughter and I) saw regular and good CC's and CG's on the way up the hill but by the time we found somewhere to park that had a view and no streetlights, were disappointed by the lack of activity (~ 2130 EDT).

   The 2nd cell ( the one passing over home ~7-8pm) was definately the most electrically active.
  The 1st cell  ( the one obs. from seven hills) had the best looking base .. .also commented on by Dave C and others.

  Dave N