Topic: Eastern NSW Severe storms / supercells 16-17 March 2011

[Jimmy Deguara]

Storm Chase 16th March 2011

Made a day of what was lets say an interesting situation according to the models. Fortunately, storms did develop by mid-afternoon and we ( Imelda, Jimelle and I) made our way to Dungog. the first cell was definitely multicellular at first and then as the storm passed over Dungog, my eyes almost popped out of my head! The storm had consoldated into an organised storm most likely supercellular from this point on. We made our way out toward Gloucester - most would know this takes some time due to the windy roads! South of Gloucester and we could see the core with lightning hammering down from the anvil as well as the core.

On the north side, we were greeted with reasonable structure although the green tinge was sure a reminder of immenent hail. Light NE winds were soon replaced by outflow. We headed north and intercepted hail just east of Gloucester. The larger hail had crossed the hail south of Gloucester - measured to 5cm! Some solid balls amongst them.

We did attempt to make our way down to Singleton cell but the cell weakened as anticipated before we could get to it.

Pictuures later.

Regards,

Jimmy Deguara

[Michael Bath]

Been a long lived coastal supercell today. It formed near Nelson Bay at 11am EDT and has tracked through a number of coastal locations including Forster, Crowdy Head and Port Macquarie. It is still going strong approaching South West Rocks (Smoky Cape) at 5pm


256km Radar Loop for Newcastle, 22:00 16/03/2011 to 08:00 17/03/2011 UTC

[Michael Thomas]

Quite an impressive storm. One thing that I was impressed by was the lower-level moisture. In Taree and Port Macquarie, the pre-storm obs were 23/22 and 24/22, respectively. That results in some seriously low LCL's. The Williamtown sounding shows that the lowest 200 mbar was almost totally saturated. This rich low-level moisture resulted in quite an unstable environment despite the low surface temps. Couple that with 30-40 knot WSW winds at 500 mbar and ~10 knot E/ENE winds in the lowest 100 mbar and you have quite a decent storm setup.

[Ben]

Still waiting on pics Jimmy Couldn't get out on the 16th had uni unfortunately and after seeing pics of the Singleton Supercells and hearing about the Gloucester one was quite irritated. Saw radar the morning of the 17th and conditions were actually very favourable and at Raymond Terrace I decided to take off after that left moving supercell that went from Forster-Smokey Cape. Intercepted it at Port Macquarie and got ahead of it, before attempting to find views near Crescent Head but alas trees + scud greatly ruined the view, I could only get one photo of one side of the storm at South Kempsey
   
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This image was taken probably as it was weakening. Around Port Macquarie its structure was better. Picture this image, but more defined, with the striated shelf curling across the southern horizon with a wall cloud on the SW horizon. Unsure re any rotation. During the kind of corepunch encountered some extreme rainfall + strong winds.

[Jimmy Deguara]

Hi Ben et al,

I have finally got the images back up. I was seriously busy during the week.

Singleton supercells were cleaner though easier looks more from a distant. I am visturally underneath - road network pathetic. I didn't think I would make it in front on time!

Intensifying/orgasing over Dungog


Then this







Then south of Gloucester finally in front






Inflow band or inflow stinger/beaver tail  - more mid level feature - David C what are your thoughts?






More images as usual

http://australiasevereweather.com/photo/index.php?twg_album=089___2011%2F290___16+march+2011+jd

Regards,

Jimmy Deguara

[pingtang]

Thanks for the photos and reports Jimmy and Ben.

Im quite irrited now,  On Wednesday morning I was VERY close to taking a sickie to chase the Upper Hunter. I'm always interested in chasing on a workday when theres shear about and the potential for supercells. The severe storm the previous day near Bombala also increased my interest. The Broke/ Singleton area was the general plan. Unfortunately I made a last minute decision to go to work, I thought the Southerlys could ruin it with the models showing an estabilised southerly pushing into the Hunter before mid day.  As it turned out, the Southerly didn't reach the Upper Hunter until 4-5pm and it actually helped trigger storms further south along the Southern Tablelands.

Whilst at work I knew I made the wrong decision .Just before the S'ly (8:30am) I had a brief look outside and the sky looked very untsable.Heaps of accas about,and lots of lovely blue sky.

Work finished at 2:30pm. I could finially chase but the souttherly was fully established in Nowra was thick stratocumulus. I was suprised to see decent storms on the radar to my SW( I couldn't see them due to the scud)

I chased to the Southern Highlands and attempted to intercept the Goulburn/ Marulan severe storm. Unfortunately it moved into no-mans land,and I only got distant glimpses of the structure. It looked quite organised with the heavy precip curtain seperated from the very low RFB, and bolts were regulary occuring just ahead of the precipin a tight area. Unfortunately this was occuring 20kms from me. Inflow was moving quickly into the storm, but this was very cool air. The storm slowly died as a result.

[Jimmy Deguara]

Pintang,

I know I have said this another time but definitely this time do not feel bad about your decision. In hindsight it is easy to suggest otherwise!

To tell you the truth, most people would not have taken the day off to chase. You guessed it the southerly was the negative feature - imagine spending a tank of fuel on outflow dominant crap. Had the target been further north, I would not have even chased. For you that distance suggested a bust would have been hurtful. The storm structures really surprised me particularly the inflow etc. There was nothing in the models that suggested to me the type of cells that occurred was to occur.

And then the day after with Ben - why would someone chase with a model suggesting 800 CAPE - I know adjusted values would have suggested otherwise. (I could have chased on this day as well but I had work to do and the risk was there as well). Even with modest instability you could have storms tracking boundaries which I suspect was occuring with the one tracking the coast.

Interesting couple of days nevetheless and given the accuracy of the models these days, surprises are rare!

Regards,

Jimmy Deguara 

[Ben]

Fantastic photos there Jimmy!! Looked like a nice storm!!! Apparently there was a tornado/waterspout in that left moving supercell offshore on the 17th that went through Port Macquarie. Oh how I wish I was on the coast! Here is the link http://www.portnews.com.au/news/local/news/general/couples-high-seas-escape/2108418.aspx?storypage=1

[Jimmy Deguara]

I would not be surprised given the low LCLs on the day. There is nothing I could find on Youtube. It would be interesting to know what it was.

Ben, chasing the coast would have been difficult. You would have had to have picked a spot and then say goodbye to the storm in normal circumstances.

Nice curved shelf cloud.

Regards,

Jimmy Deguara