Storm Potential for central NSW 29th November 2011

Update: Michael Thompson posted this image of a explosive dryline supercell from the 29th November 2011 event:

Given the strong instability and generally decent turning profile, there is the likelihood of severe storms over central NSW this afternoon and evening. CAPE values show the atmosphere is more than sufficient for hailstorms with very warm humid air and sufficient cool temperatures aloft. I would not be surprised if there are a few supercells today if storms can remain isolated. Given the capping particularly to the west, isolated storms are a decent chance.

I guess we shall see what happens.

By the way, I would again like to mention that the GFS is being contaminated by data and over estimating moisture in the Riverina - I would only anticipate higher based storms in this region.

Regards,

Jimmy Deguara

18 thoughts on “Storm Potential for central NSW 29th November 2011

  1. Ben

    Certainly has been an incredible outbreak so far. Apparently amazing lightning displays in across the southern tablelands and coast, a potential LP Supercell near Bathurst, and a supercell in the Forbes and Parkes area with cricket ball size hail. I was lazy after having no sleep and sitting a long exam and didn’t head out yesterday as I didn’t want to drive more than a couple of hours, certainly paid the price there. Today I work, otherwise I’d have been in the Hunter, where there is quite a nice line in the Port Stephens area. Hopefully Sydney can do something.

  2. Jimmy Deguara Post author

    Ben,

    Have you seen any pictures of the cricket ball sized hail? Storms along the dry line would have been rather high based and motoring along at some speed.

    The lightning show was simply incredible and very persistent!

    Nice LP structure Nick! Certainly quite a few right moving LPs on this day! Interesting to consider the hodographs favouring right movers!

    Regards,

    Jimmy Deguara

  3. Weather Freak

    Hey Jimmy,

    Thanks that thunderstorm was the most spectacular i have seen over Wodonga in my life :) and it was a great opportunity to be able to film some lightning which i have been trying to photograph for ages to no success lol but i was very happy to get it on film as then its there and if i can get it to the right shot i may be able to get stills off it if i am lucky enough too. Not quite as good as an original photo though :) also since i posted up those shots i looked for more articles in our local paper about it on the internet and since came across this photo gallery of the storm that passed over us. was wondering if it was a Supercell? am not sure but when i looked closely at my daytime videos it seemed like there could have been a bit of rotation in the clouds? what i had of it anyway though i could be wrong with not being very experienced at it all lol.

    Anyway here’s the gallery photo link i found to our local border mail :)

    http://www.bordermail.com.au/multimedia/32223/404478/reader-photos-border-lashed-by-violent-storm.aspx

    Hope it gives you more of an idea of the storm that passed over Wodonga as i am not totally sure all i know is it was so magnificent and i loved every minute of it :)

    Weather Freak :)

  4. Ben

    Going by that photo it looks to me it had a pretty nice rain free base on it to me, but don’t see any signs of it being supercellur :) You don’t need supercells to give damage/savage lightning displays!!!

    Jimmy, no I have seen no photos of the hail thus far. However, the person I heard it from lives in a separate state so shall give them time to get their pics up :-)

  5. Weather Freak

    Ben which photo are you talking about can i ask? is it the one in the link or the one displayed on the first page by nick? just wondering but thanks :) nice to know as i am still a beginner when it comes to storm structures :) And can i also ask what is RFB? Thanks

  6. Jimmy Deguara Post author

    Certainly looks like the storms in SE NSW were reasonably high based which explains the speed they were travelling given the modest wind shear!

    The only storms that looked like they were anchored if not briefly in the lower boundary layer were the couple of storms near Goulburn. They made a left move briefly before racing off SE once more probably crossing the boundary and remaining elevated.

    Regards,

    Jimmy Deguara

  7. Michael Thompson

    Chased with Michael Keene and Steve Feral to the Central West on Tuesday/Wednesday. What a two days of highs/lows/missed opportunities/lucky strikes.

    At Lithgow on Tuesday morning we had to make a decision on playing the Gulgong/Dunedoo region, or Parkes/Forbes. We choose an in between option of Wellington, which ironically may have cost us a direct intercept of the Sofala nuclear cell (with perhaps hail damage to our cars), but playing just Gulgong/Dunedoo may have led us to miss the Parkes action later.

    At Wellington at 2pm it looked grim, however in the space of 30mins the struggling convection transformed and I bravely made a call that our first storm was not that far away. Unfortunately this storm developed just to our SE, as in 15kms SE, which if you are familiar with the countryside placed it in that popular storm development area of “no mans land”. We tracked this storm southwards along the Wellington – Orange road via Mumbil, at times getting within 20kms of the storm. We have no pics or video, but there were several clear air CG’s witnessed.

    Obeying murphies law, this storm died before it reached the Great Western Hwy. We then headed towards Millthorpe with an intention of heading westwards to Cowra – Forbes, but became distracted by the nuclear development south of Mudgee.

    This cell tracked almost due south, slightly rightwards of the main cells. There were at times odd mid layer cloud streaks into the cell. The solid hail shaft connection to ground was one of the most distinct I have seen in years. The question was not whether it contained hail, just the size.

    All along we were aware of the developing line out on the plains. Although I did not like the option our plan was to secure accommodation at Orange (poor Steve had been driving his own car since 4:30am, while us two Michaels had shared), and perhaps intercept the line after dark west of Orange. However all Orange motels were booked out, a case near everyday of the week I am told due to the the modern day gold rush. Therefore we pushed on to Manildra and Parkes. Just on dusk the updraft of a cell west of Parkes come into view, although 150 kms away, it looked a beast and we saw one clear CG strike out into the clear slot between two storms, it must have landed 20-20kms from the storm!

    We chucked our bags into the first motel we saw at Parkes and bolted down the road 20kms and saw some brilliant lightning. Conditions with 25 knot surface winds, light rain and B double trucks doing 120kms past you we far from ideal – not to mention the storm itself doing an estimated 60-70kms per hour.

    This first shoot shows the storm just west of us, at this stage strong, and that cloud band looked inflow, not outflow.

    Within a short 10 minutes the same storm had moved SE out of site and we had an interlude of anvil rain before the next cell trained through.

    Picture spoiled by power lines and some rain drops on lens.

    We then headed back to Parkes, but got surprised by a cell right in town. this was a little nasty with horizontal rain. Michael K captured on video the bolt of the day – a nice power flash!

    Day two was very disappointing. Hopes were high with a 8am storm at Parkes with some well scattered CG’s.

    However as we drove NE to Peak Hill and Dubbo we keep getting overtaken by mid layer convection lines that turned into rain with embedded lightning. We threw this off at Dunedoo, but by then everything was a mid layer cloud feast of epic proportion. We did get within a 100kms of the cells north of Newcastle, but there was no structure to be seen at all.

    Jimmy’s original model post is pretty much how it ended up. The dry line ended up being the focus point for the most serious convection, but I did not have the faith to chase that far west,risking extra kilometres for a possible bust. Also very interesting and not normally seen on an Australian map is the pronounced dryline bulge. It is no coincidence that the nasty cells described by others developed here.

    As for my next chase….I would like something that moved a little slower.

  8. Jimmy Deguara Post author

    Hi Michael,

    Excellent storm activity in your post! There is no doubt there was ample spectacular lightning activity on this event! However, I am more interested in the daytime dryline behaviour of which yours above also displays. There is clean structure with NO crap in front. These storms in my opinion would have dropped comparable hailstones to what has been posted on the forums – golf balls to about 5 to 6cm in diameter! The speed of the storms and the dominance of right movers is probably explained by hodographs that favoured right movers and slightly higher bases.

    Anyway, I am glad you guys got out and about amongst it all.

    Regards,

    Jimmy Deguara

  9. Jimmy Deguara Post author

    Hi Michael,

    …and B double trucks doing 120kms past you we far from ideal…

    Oh yeah!! Jimmy knows what can happen with this!! Filming the rotating wall cloud near Nyngan in the supercell outbreak 2004, two B doubles came racing past. David C spiced up the story a little suggesting one of them past a touch closer than the other. The end result, the $7000 cannon 3CCD video camera lay snapped on the roadside! Lucky a tornado did not drop down or suicide would have been an option haha! I can laugh now – but then….

    Impressive lightning anvil crawler Michael. To tell you the truth, I actually don’t mind the pole in the picture – it adds dimension.

    Regards,

    Jimmy Deguara

  10. Jimmy Deguara Post author

    Hi Michael,

    Also very interesting and not normally seen on an Australian map is the pronounced dryline bulge.

    Can you show evidence of this? I did not take note of it. I assume there was some sort of surface low in the area? Nevertheless, with higher bases, not much would have occurred in terms of enhancing any chances of tornadoes given the high dew point deficit.

    Regards,

    Jimmy Deguara

  11. Michael Thompson

    Video of the ‘nuclear’ cell near Bathurst, also a couple of extra pics.

    The video below does not do justice, and as usual in Australia it is glimpses between trees. The first sighting we got of ground level showed a nasty cloud curtain on the SE side of the hail shaft, sorry this was not captured on video.

    http://www.youtube.com/watch?v=ncwvZpqykLA

    This picture has had the blown highlights in the updraft column restored to show just how powerful and boiling the updraft was. This picture was taken 15-20minutes after the one in my earlier post. The overshoot has fallen back – this would be an interesting time at ground level for hail.

    This view is looking south from the same spot as the pic above was taken. It shows the storms in the Cowra/Boorowa area. Although 100kms away the chances of mowing down these storms with the speed they moved was zero.

  12. Jimmy Deguara Post author

    Hi Michael,

    Thanks for the video. Definitely a hail core there!

    Sorry to bring it up once more, I am more wandering where the information you may have come across regarding the concept of the dryline bulge? I thought initially it was merely a wind change but I was wandering whether you may have been referring to a dryline bulge in a different area.

    Thanks.

    Jimmy Deguara

  13. Jimmy Deguara Post author

    Weather Freak,

    I just noticed a transformer flash in the night time lightning after about 8 seconds or so. You will see a green glow just after a lightning flash.

    Jimmy Deguara

  14. Michael Keene

    Well theres probrably no point writing up a chase report, as it will mirror Michael Thompsons report. My photos are almost identical as well.

    However, I do have a fair bit of video that i’d like to show. I’m currently having trouble uploading onto youtube, but I wont give up.

    Like Michael I have video of the Bathurst supercell, but some of my video was taken 10minutes before Michaels, so it will be worth seeing. I also have video which contains distant glimpses of the powerful updaft that was barreling towards Parkes/ Forbes. Also, plenty of nightime lightning to show as well. So stay tuned, it will be uploaded soon.

    Anyway, heres a teaser. Lightning and a power transformer flash just south of Parkes.

    http://youtu.be/qpQKHtR3T0A

    Enjoy.

  15. Jimmy Deguara Post author

    Hi Pintang (Michael),

    Nice power flash! I would not want my computer connected without a power surge protector with one of those outside my house!

    Jimmy Deguara

  16. Harley Pearman

    I did a storm chase on this day around the Marulan / Goulburn region. At Marulan two small storms passed over me. The second one produced hail and some of the hail was oddly shaped. Following that, I chased a third storm to Goulburn where I took video of lightning just to the south of me. I understand that storm passed over the Batemans Bay region.

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